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Glossary of Medical Terms
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A
Term Description
Abdomen The part of the body that lies between the chest and the pelvis and encloses the stomach, intestines, liver, spleen, and pancreas
Abdominal cavity The space bounded by the abdominal walls, diaphragm, and pelvis and containing most of the organs of digestion, the spleen, the kidneys, and the adrenal glands.
Ablation The removal or destruction of a body part or tissue or its function. Ablation may be performed by surgery, hormones, drugs, radiofrequency, heat, or other methods
Abscess A localised collection of pus
Absence Seizure A type of generalized seizure, which does not result in loss of consciousness but an altered state for a very short period of time, usually lasting less than 20 seconds. Also called a Petit Mal Seizure
Acalculia Loss of the ability to solve simple arithmetic problems
ACE inhibitors ACE (angiotensin converting enzyme) inhibitors are a class of vasodilators, drugs that open ("dilate") the arteries, lowering blood pressure and therefore the heart's workload
Achondroplasia A genetic disorder of bone growth (the long bones) that causes a common form of dwarfism. People with this condition have a normal body but short arms and legs
Acidosis A condition in which the blood is more acidic than normal. This may be due to a build up of carbon dioxide as a result of respiratory failure, or of acid substances, e.g. hyperglycaemia in diabetes mellitus (diabetic ketoacidosis)
Acoustic Relating to sound or the sense of hearing
Acquired Immune Deficiency Syndrome (AIDS) A severe immunological disorder caused by the retrovirus HIV. There is an increased susceptibility to opportunistic infections and to certain rare cancers, especially Kaposi's sarcoma. Click here for more information about HIV/AIDS
Acromegaly Increase in size of hands, feet and face due to excessive production of growth hormone by a tumour of the pituitary gland
Acromioclavicular joint A joint between the acromion (part of the shoulder blade) and the clavicle (collar bone)
Acromion The roof, or highest point, of the shoulder that is formed by a part of the scapula, or shoulder blade
Acuity Clearness or sharpness; usually of vision
Acute Having rapid onset
Addisons disease A rare disorder caused by deficient secretion of hormones by the adrenal gland, resulting in weight loss, weakness, and low blood pressure
Adenocarcinoma A malignant neoplasm derived from transitional epithelium
Adjuvant Add on treatment used in combination with primary (main treatment)
Adrenal glands Two triangular glands located above each kidney. These glands produce steroid hormones and adrenaline
Adrenaline A hormone produced by the adrenal glands
Aerobic With oxygen
Affect Feeling or emotion as distinguished from cognition, thought, or action. Affect means mood. Affective disorders are disorders of mood
Ageing The process of growing older. It includes a reduction in strength, endurance, speed of reaction, agility, basal metabolism, sexual activity and hearing acuity. The bones are more brittle, the skin drier and less elastic and the teeth are shed. Click here for more information about Ageing
Agitation A state of extreme emotional disturbance, restlessness with inability to concentrate
Agnosia A loss of ability to recognize objects, persons, sounds, shapes or smells while the specific sense is not defective nor is there any significant memory loss. It is usually associated with brain injury or neurological illness, particularly after damage to the temporal lobe
Agonist The muscle directly engaged in contraction. In bending the elbow, the biceps muscle is the agonist
Agoraphobia Morbid fear of open space, and social situations
Agraphia Loss of the ability to write
Akathisia Restlessness of arms and legs. This can be a side-effect of anti psychotic treatment
Akinesia The absence or poverty of movements
Albinism (Albino) Partial or complete lack of pigment in skin, hair and eyes
Albumin (Serum albumin) One of the body's proteins. It is the most abundant of the proteins in the blood plasma
Albuminuria Presence of albumin in the urine usually indicating disease of the kidneys
Alcoholism Alcoholism is a term applied to habitual excessive alcohol consumption. Click here for more details about Alcohol Related disorders
Allergen A substance which, when introduced into the body most often through being eaten, inhaled or skin contact, provokes an allergic state in sensitive individuals. E.g. pollen
Allergy (Allergic State) Sensitivity to a particular foreign substance [Allergen]. E.g. Asthma and hay fever
Alpha1 Antitrypsin deficiency An inherited deficiency of a trypsin-inhibiting serum protein that may increase one's susceptibility to emphysema and cirrhosis.
Alport's Syndrome An inherited syndrome marked by progressive nephropathy and nerve deafness and sometimes ocular defects.
Alveoli Very small air sacs in the lung
Alzheimer’s disease A progressive, neurodegenerative disease characterized by loss of function and death of nerve cells in several areas of the brain, leading to loss of mental functions such as memory and learning. Alzheimer’s disease is the most common cause of dementia
Ambulatory Walking
Amenorrhoea Absence of menstruation
Ammonia A colorless, pungent gas used to manufacture a wide variety of nitrogen-containing organic and inorganic chemicals
Amnesia Total or partial lack or loss of memory; inability to remember past experiences
Amnestic Syndrome An altered psychologic state where memories are not recorded and are lost
Amphetamines A stimulant drug. Used in treatment of narcolepsy and ADHD where it helps control hyperactivity
Amyloid A protein substance often deposited around and within blood vessels, for example in the kidneys as a result of chronic infection (e.g. TB) or autoimmune disease
Amyloidosis A disorder marked by the deposition of amyloid protein in various organs and tissues of the body.
Amyotrophic lateral sclerosis A type of motor neurone disease characterised by atrophy of the muscles of the hands, forearms and legs and spreading to involve most of the body
Anaemia A deficiency of red cells or their haemoglobin in the blood. Click here for more details about Anaemia.
Anaerobic Without oxygen
Anaesthesia A partial (local) or total (general) loss of feeling or sensation
Anaesthetic A drug, which removes sensation. With a local anaesthetic, the feeling is removed only from part of the body. With a general anaesthetic, the patient is unconscious
Anal Canal The terminal portion of the alimentary canal, extending from the pelvic diaphragm to the anal orifice.
Analgesia Pain relief
Analgesic A drug that relieves pain [such as aspirin, paracetamol, morphine]
Anaphylactic shock
Anaphylaxis
An extremely severe form of allergic reaction, which can be fatal
Anastomosis An end-to-end union or joining up of two structures usually blood vessels or loops of intestine
Anatomy The science of the structure of living organisms
Aneurysm A localised ballooning of the walls of an artery, most commonly affecting the abdominal aorta, but also arteries of the brain
Angina Pectoris A pain in the chest usually caused by exercise due to reduced circulation of blood in the coronary arteries, which supply the heart muscle. Click here for more details about Ischaemic Heart Disease.
Angio-oedema Swelling of the deep tissues of the face and throat which may be life threatening. Can occur alone or accompany anaphylaxis and/or urticaria. Formerly known as angio-neurotic oedema. Also used to describe deep tissue swelling of the hands, feet or genitals. Click here for more details about Urticaria.
Angiogram/Angiography X-ray examination of blood vessels after injection of a special fluid, which shows up on the x-rays. Click here for more details about Angiogram (Angiography)
Angioplasty
(Cardiac Catheterisation)
A procedure that identifies possible problems with your heart or its arteries. A thin plastic tube, called a catheter, is inserted into a blood vessel in the groin or arm. The catheter is guided up toward the heart. A special dye is injected into the catheter so X-rays can show any artery blockage or other heart problems
Angiotensin II An octapeptide that is a potent vasopressor and a powerful stimulus for production and release of aldosterone from the adrenal cortex.
Anhedonia Total lack of interest in and enjoyment of hobbies / pleasure activities
Ankle brachial pressure index A ratio measuring the difference in blood pressure in the arteries used as a test for blocked / narrowed leg arteries.
Ankylosis Severe or complete loss of movement at a joint usually due to the abnormal joining of bones to each other
Annulus A ring like structure, or any body part that is shaped like a ring. E.g. inter-vertebral discs consist of a tough outer ring of fibrous material (the annulus)
Anomaly An abnormality, a deviation from normal
Anomia A form of aphasia (loss of language capability caused by brain damage) in which the subject has difficulty remembering or recognizing names which the subject should know well. The subject speaks fluently and grammatically and has normal comprehension, and the only deficit is trouble finding appropriate words
Anorexia An abnormal loss of the appetite for food. Anorexia can be caused by cancer, AIDS, a mental disorder (i.e., anorexia nervosa), or other diseases
Anoxia Absence, or deficiency of oxygen
Antacid An agent that counteracts acidity
Antagonist A muscle that relaxes while another contracts; "when bending the elbow the triceps are the antagonist"
Antenatal Before birth; also called prenatal
Anterior Nearer to, or at the front of the body
Anterior Segment The anterior segment is the front third of the eye that includes the structures in front of the vitreous humour: the cornea, iris, ciliary body, and lens
Anti-androgen drugs Drugs that prevent the development and maintenance of masculine characteristics on responsive tissues. Block the action of the male sex hormone (testosterone).
Anti-inflammatory Medicine used to relieve swelling, pain, and other symptoms of inflammation
Antiarrhythmic A drug or procedure that lenscounters or prevents cardiac arrhythmia
Antibiotic A drug that inhibits the growth of, or kills micro-organisms such as bacteria (germs), and is used to prevent or treat infectious diseases
Antibody A protein produced by the body in response to a foreign substance (antigen) such as bacteria. The antibody combines with the antigen to destroy or neutralize it and prevents/cures infection
Anticholinergic drugs Drugs used to increase the effect of nerve transmitters that reduce spasm. Can also be used in asthma treatment
Anticoagulant A substance that is able to decrease or prevent the clotting of blood
Anti-convulsant drugs (Anti epileptic medication) Drugs used to treat epileptic seizures. If used for Epilepsy click here for more details about Epilepsy.
Anti-depressant Drugs used to relieve or prevent the symptoms of mood or anxiety disorders
Antiemetic Drugs Agents that prevent or arrest vomiting
Anti-histimines Drugs that combat the histamine released during an allergic reaction
Anti-hypertensive agent Drugs used to relieve or prevent the symptoms of mood or anxiety disorders
Anti-muscarinic drugs Effective against the toxic effects of muscarine (a highly toxic alkaloid related to the cholines and having neurologic effects)
Antigen A substance that when introduced into the body causes the formation of antibodies
Anti-psychotic drugs A group of drugs used to treat psychosis. E.g. schizophrenia
Anti-resorptive drugs Medications that work by preventing natural breakdown of bone are called anti-resorptive agents. They inhibit bone removal or resorption and tip the balance toward bone rebuilding, thus increasing bone mass
Anti-spasmodic Preventing or relieving convulsions or spasms.
Antithyroid drugs Drugs used in the treatment of excessive activity of the thyroid gland
Antiviral anti-retroviral drug An agent that destroys or inhibits the growth and reproduction of viruses
Anuria Absence of urine output
Anus The outlet of the rectum
Anxiety Anxiety is an unpleasant emotional state characterised by fearfulness and unwanted and distressing physical symptoms. Click here for more details about Anxiety Disorders.
Anxiety Disorder A generalised, excessive anxiety persistent for more than 6 months
Anxiolytic A tranquilizer used to relieve anxiety and reduce tension and irritability
Aorta The main trunk of the arterial system of the body, which carries, oxygenated blood from the left ventricle of the heart to all parts of the body
Apathy/Apethetic The lack of emotion, motivation, or enthusiasm. Apathy is a psychological term for a state of indifference - where an individual is irresponsive or "indifferent" to aspects of emotional, social, or physical life
Aperture An opening or orifice
Apex The pointed end of a structure
Aphakia Absence of the lens of the eye
Aphasia Loss of ability to express oneself or comprehend language because of brain damage
Apnoea A temporary suspension of breathing, for several seconds
Appendicitis Inflammation of the appendix, which is a small blind tube in the gut
Apraxia Partial loss of ability to perform coordinated movements
Aqueous humour Clear fluid in the eye - provides nutrients and determines intraocular pressure
Arachnoiditis A condition in which there is inflammation of the Arachnoid membrane surrounding the brain and spinal cord
Areflexia The absence of reflexes
Arrhythmia Disorder of the heart rhythm, irregular heartbeat (also called dysrhythmia)
Artery A blood vessel that carries blood away from the heart
Arthralgia Pain in one or more joints
Arthritis Inflammation one or more joints which causes pain and difficulty in moving
Arthroplasty The surgical restoration of the integrity and functional power of a joint. Meaning literally 'to refashion a joint'; i.e. replacing the joint by a complete or partial replacement with an artificial joint
Arthroscopy A procedure for examining the interior of a joint
Articular Relating to the joints
Articulate 1) To join together
2) To put into words
Articulation 1) Where two bones meet to form a joint
2) The process in which speech sounds are formed
Artificial pacemaker A medical device that produces and delivers electrical signals to the heart to maintain a regular heart beat
Ascites Abnormal accumulation of fluid in the abdomen
Aseptic Free from any infectious material
Asperger's Syndrome A complex brain dysfunction related to Autism
Asphyxia Interference with the oxygen supply to the body, which in the absence of appropriate measures, will lead to unconsciousness and death
Asthenia Weakness, lack or loss of strength; debility
Asthma Asthma is a common condition of the lung airways in the respiratory tract. Although the cause is not completely clear it is known that there are many contributory factors and it is also known that the number of people affected by the condition is rising
Astigmatism An irregularity of the lens or cornea of the eye producing faulty vision
Asymmetrical Lack of symmetry, i.e. lack of similarity between corresponding parts or organs on opposite sides of the body that are normally alike
Asymptomatic Without obvious symptoms of disease
Ataxia Lack of muscular coordination; lack of precision; unsteadiness
Atelectasis A collapsed or airless state of all or part of a lung
Atheroma Fatty material that can build up within the walls of the arteries and a reduction of blood flow, on to which clots may form
Atherosclerosis A disease process in which fatty substances are deposited along the walls of arteries, which can lead to obstruction of blood flow
Atlanto-Axial joint The first joint in the spine. (The top vertebra is called the atlas and the second is called the axis)
Atonic Seizure A type of generalized seizure characterized by sudden loss of muscle tone, causes the head or body to drop suddenly with falling & potential injury. Recovery in a few seconds to a minute. Also called a drop attack
Atopic A tendency to develop hypersensitity reactions in response to allergens
Atrial fibrillation A very fast and irregular beating of the atria (the upper two chambers of the heart)
Atrium The two upper chambers of the heart
Atrophy Wasting away or decrease in size of a part of the body
Attention Deficit Hyperactivity Disorder (ADHD) A common developmental and behavioural disorder
Audiometry Evaluation of an individual's hearing
Auditory Meatus Either of the passages in the outer ear from the auricle to the tympanic membrane
Auditory Nerve The eighth cranial nerve, which connects the inner ear to the brainstem and is responsible for hearing and balance
Aura A feeling or sensation that precedes an epileptic seizure or a migraine
Autism/Autistic Spectrum Disorder A brain disorder that begins in early childhood and persists throughout adulthood; Affecting communication, social interaction, and creative or imaginative play
Auto immunity The production of antibodies against a person's own tissues
Automatism A condition in which actions are performed without consciousness
Automatic Behaviour Automatic Behaviour or purpose; sometimes follows an epileptic seizure
Autonomic Nervous System A part of the nervous system, which is not under conscious control
Autonomous mood Mood does not react in response to circumstance
Auto Somal Refers to a gene which is not responsible for determining the sex of an individual
Avascular necrosis Death of bone tissue due to interruption to its blood supply. E.g. Perthes disease (affecting ball of hip joint)
Avascular Tear A tear that is it doesn't bleed if cut and doesn't have blood vessels inside. As a result of this avascularity it doesn't have the ability to heal itself
Axilla The armpit
Axis 1 disorders Axis 1 disorders are psychiatric clinical disorders that include depression, anxiety disorders ,bipolar disorder and schizophrenia

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B

Term Description
Back Pain
Back Pain is the commonest orthopaedic complaint. Pain may arise from the vertebrae, inter-vertebral discs, facet joints, ligaments, the spinal canal, spinal cord or nerve roots, but most commonly no structural abnormality can be identified to account for the person’s back pain
Bacterium A single-celled microorganism consisting of a single double-stranded DNA molecule. They multiply by cell division and generally have a very high rate of population growth and mutation.
Bailie-Lovie test chart A test chart that measures contrast sensitivity
Balloon Angioplasty (PTCA) A procedure in which a balloon-tipped catheter is inserted usually via the femoral (groin) artery and manoevered into the narrow heart artery. The balloon is then inflated to stretch the vessel opening and improve blood flow through it
Barbiturates Controlled substances that increase heart rate and awareness in preparation for fight or flight
Barium Meal or Swallow X-Ray examination of the upper gastrointestinal tract after swallowing a radio-opaque substance
Basal Ganglia In the brain, four neuron clusters crowning the thalamus, which help to regulate body movement by relaying information from the cerebral cortex to the brainstem and cerebellum
Benign Not malignant
Benzodiazepines A group of psychotropic drugs that have a hypnotic and sedative action, used mainly as tranquilizers for the control of symptoms due to anxiety or stress and as a sleeping aid for insomnia. They may also be used help suppress dystonic movement and in the treatment of Status Epilepticus and febrile seizures
Beta adrenergic blocking drugs
(Beta Blocking Agents)
Drugs that may help to reduce the effects of tremor associated with the spasm
Beta-agonists An agent, such as Salbutamol, that stimulates beta-receptors in the autonomic nervous system
Beta-blockers (Beta Blocking Agents) A group of drugs, which reduce the workload of the heart by blocking certain actions of the sympathetic nervous system. They slow the heart rate and lower blood pressure and other symptoms caused in frightening situations. They may also reduce the effects of tremor associated with spasm
Biliary Cirrhosis Cirrhosis is a condition that destroys healthy tissue leaving scar tissue, which blocks the flow of blood through the liver. There are several causes including alcohol dependency
Bilateral Relating to both sides of the body
Bile A greenish-yellow fluid secreted by the liver and stored in the gallbladder. Helps in food digestion
Bilirubin A bile pigment derived from the degradation of hemoglobin during the normal and abnormal destruction of red blood cells
Binocular Relating to both eyes
Biochemical Chemical processes involving human biological function
Biofeedback A behaviour modification therapy designed to develop the ability to control the involuntary nervous system. After learning the technique, a person may be able to control heart rate, blood pressure, skin temperature and to relax certain muscles
Biological symptoms Usually a physical sign of a disease. Any perceptible, subjective change in the body or its functions that indicates disease or phases of disease, as reported by the patient
Biopsy Removal of a sample of tissue, which is then examined under a microscope
Bipolar Disorder A disorder in which a person can experience recurrent attacks of depression and mania or hypomania. It used to be called manic depression
Bitemporal hemianopia Loss of temporal (lateral) visual field in each eye
Bladder Any of various distensible membranous sacs, such as the urinary bladder that serve as receptacles for fluid or gas
Blepharospasm Acute spasm of the muscles around the eye, causing involuntary blinking, or almost complete, involuntary, closure of the eyelids
Blood pressure Pressure exerted by blood as it presses against and stretches blood vessels, especially arteries
Blood Tumour markers A substance, released into the circulation by tumour tissue, whose detection in the serum may indicate the presence of a specific type of tumour
BNP Blood Test A B-type natriuretic peptide (BNP) blood test, identifies a hormone which is indicative of either heart or renal failure
Body cavity A space within the body that contains various organs
Body Mass Index (BMI) A method used to gauge whether or not a person is overweight. BMI is calculated by dividing a person's weight (in kilograms) by his or her height (in metres, squared)
Bone Anchored Hearing Aid Bone Anchored Hearing Aids are surgically implanted devices that transmit sound directly to the inner ear through the bones of the skull
Bone Densitometry Test An X-ray technique to measure bone density and detect Osteoporosis
Bone Marrow The soft, fatty, vascular tissue filling the cavities of bones
Bone Scan (Bone Scintigraphy) Procedure in which a radioactive substance is injected and the radiation emitted from bone is measured. The aim is to identify abnormal processes involving the bone (such as fracture, tumour, infection etc)
Botulinum toxin type A (Botox) Nerve toxins given by local intramuscular injections weaken overactive muscles and reduce dystonic symptoms. E.g. Blepharo spasm
Bouchard’s nodes Bony nodules spurs that occur on the middle finger joints
Bradycardia An abnormally slow heartbeat (usually less than 50 beats per minute)
Bradykinesia An abnormal slowness of movement, sluggishness of physical and mental responses
Bronchi Large tubes in the respiratory passageway branching from the trachea (windpipe) through which air flows in and out of the lungs
Bronchial tree The bronchial tree is the branches from the main bronchi that penetrate the lungs to deliver air to minute lung tissue responsible for gas exchange
Bronchial tubes The main breathing tubes leading from the trachea into the lungs. 2. The large air tubes leading to the lungs. One tube is called a bronchus, both tubes are called bronchi
Bronchioles The smallest sub-division of the bronchi at the end of which are the alveoli
Bronchiectasis A chronic disorder in which there is loss of the normal tissue and expansion of lung air passages
Bronchiolitis Respiratory infection that affects the bronchioles, the smallest airways in the lungs
Bronchitis Inflammation of the bronchi. It may be acute or chronic
Bronchodilators Drugs used in the treatment of asthma, which open up the airways in spasm
Bronchogenic carcinoma Cancer of the lung
Bronchopulmonary dysplasia A chronic lung disorder usually seen in very premature infants. It results in Respiratory Distress Syndrome
Bronchus One of the larger passages conveying air to a lung (right or left primary bronchus)
Bruce Protocol The Bruce Protocol is a description of the protocol for the increments in speed and gradient in a treadmill/exercise test. Click here for more information on the Bruce Protocol Test
Budd-Chiari Syndrome A condition producing symptomatic obstruction or occlusion of the hepatic veins causing abdominal pain and tenderness hepatomegaly (liver enlargement) ascites, jaundice and eventually portal hypertension and liver failure
Bulbar The bulbar refers to nerves controlling the muscles of the face and throat
Bulla A circumscribed, fluid-containing, elevated lesion of the skin (e.g. a blister), usually more than 1 cm in diameter
Bullectomy The excision of giant bullae (blisters) from the lung in emphysema to improve pulmonary function
Bunion A painful deformity of the bones and the joint between the foot and the big toe (the metatarso-phalangeal, MTP) joint
Bulimia An eating disorder characterised by binge-eating, self induced vomiting and purging or abusing laxatives
Bursa A sac or pouch of fluid located near joints
Bursitis Inflammation of a bursa

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C

Term Description
CABG
(Coronary Artery Bypass Graft
An operation in which a section of vein or artery is used to bypass a blockage in a coronary artery; performed to prevent myocardial infarction (heart attack) and to relieve angina
C-reactive protein (CRP) C-reactive protein (CRP) is a protein produced by the liver and found in the blood. It is raised in inflammatory conditions
Cachexia A state of gross muscle and tissue wasting, fatigue, weakness and debility, which occurs in diseases such as advanced cancer and AIDS
Calcium channel blockers A group of drugs that affect the way calcium passes into certain muscle cells. This causes arteries to relax and widen and reduce the force and rate of the heartbeat. Used mainly to treat angina and hypertension
Calculus A stone formed within the body (as in gallstones, kidney stones or urinary bladder stones)
Calipers (walking) An apparatus fixed to a boot at one end and fitting in to the groin at the other end to take the weight of a weak or injured lower limb
Callosity A localised thickening and enlargement of the horny layer of the skin (also called a callus)
Cancer A malignant tumour
Capillary A microscopic blood vessel through which material such as oxygen, carbon dioxide and nutrients or waste products are exchanged between blood and body tissues. They form a fine network in many parts of the body
Carbohydrates One of the nutrients that supply calories to the body to give it energy. Bread, pasta, rice, potatoes and cereals are examples of carbohydrates
Carcinogen
Any substance that causes cancer
Carcinoma A type of malignant tumour
Cardiac arrest Cessation of an effective heartbeat in which the heart is completely stopped or ceases to pump effectively
Cardiac Arrhythmias Also called cardiac dysrhythmia, is a disturbance in the regular rhythm of the heartbeat
Cardiac Catheterisation (Angioplasty) A procedure that identifies possible problems with your heart or its arteries. A thin plastic tube, called a catheter, is inserted into a blood vessel in the groin or arm. The catheter is guided up toward the heart. A special dye is injected into the catheter so X-rays can show any artery blockage or other heart problems
Cardiac Failure Heart or cardiac failure occurs when the pumping action of the heart is inadequate and fails to maintain proper circulation
Cardiology The study of the heart and diseases associated with it
Cardiomyopathy Disease of the heart muscle, which causes it to lose its pumping power
Cardiovascular Relating to the heart and blood vessels (arteries, veins, and capillaries); the circulatory system
Cardioversion A procedure used to convert an irregular heart rhythm to a normal heart rhythm by applying electric shock. Cardioversion may be accomplished using medications or a defibrillator
Care Programme/Plan Approach (CPA) The care plan is a written document that brings together information about social care, a medical treatment plan, domestic support, names of the professionals involved in care and actions to be taken in the event of changing circumstances. Copies of the plan are given to the patient/customer, carer, care co-ordinator and others involved. Click here for more details about Care Plan Approach/Plan Approach (CPA)
Carotid artery Either of the two main arteries in the neck below the jawbone that carry blood from the heart to the brain
Carotid Endarterectomy An operation to clear out blockages in the carotid arteries in the neck that prevent blood from reaching the brain. It is a preventative measure in people who have suffered TIAs or strokes, and reduces the risk of further TIAs or stroke
Carpal tunnel syndrome Compression of the median nerve as it crosses through the carpal tunnel in the wrist, causing numbness, pain and tingling in the hand and fingers
Cartilage (Meniscus) A translucent elastic substance of the body. It lines the ends of bones, which form joints, and is also found in other parts of the body such as the nose and ears
Cataract A translucent elastic substance of the body. It lines the ends of bones, which form joints, and is also found in other parts of the body such as the nose and ears
Catatonia A tendency to remain in a fixed stuporous state for long periods characterized by lack of awareness of one's surroundings
Catheter A thin, flexible tube that can be inserted into a body cavity or into a blood vessel; used to remove fluids, such as urine or blood, and to introduce diagnostic materials or medication
CAT Scan Computerized Axial Tomography - A special xray technique, which gives a picture of, a horizontal slice through the body at various levels
Cauda Equina Syndrome This rare condition is a severe neurological disorder that normally results from a prolapsed disc. It can lead to incontinence and even paraplegia, and is often a medical emergency
CD4 Count A measure of the number of helper T cells per cubic millimeter of blood, used to analyse the prognosis of patients infected with HIV
Cell The basic structural and functional unit of all organisms capable of performing activities vital to life
Central Nervous System That portion of the nervous system that consists of the brain and spinal cord
Cerebellar Relating to the cerebellum-part of the brain most responsible for balance, posture and co-ordinating sequences of movements
Cerebellum The portion of the brain, located in the lower, back of the head, responsible for coordination of movement and balance
Cerebral Referring to the cerebrum, often used to refer to the entire brain
Cerebrum The upper or main portion of the brain
Cerebral hypoxia Reduced amount of oxygen in the brain; often due to an interruption or reduction in the blood supply to the brain or a reduction in oxygen content of the blood
Cerebro vascular disease Disease involving the blood vessels supplying the brain, including cerebro vascular accident (CVA), also known as a stroke
Cerebro spinal fluid (CSF) Clear fluid surrounding the brain and spinal cord
Cervical Myelopathy A disorder due to spinal cord compression. There are many causes of myelopathy that include trauma, tumors, infection, vascular disease, degenerative conditions and demyelinating disorders
Chelating drug Substance, which inactivates certain metals (such as iron). It is used in the treatment of metal poisoning or where there is an excess of the metal in the body
Chemotherapy A type of treatment of malignant diseases by anti-cancer drugs
Chiropractic A health profession concerned with the diagnosis, treatment and prevention of mechanical disorders of the musculoskeletal system, and the effects of these disorders on the function of the nervous system and general health. There is an emphasis on manual treatments including spinal manipulation or adjustment
Cholangitis Inflammation of a bile duct
Cholesterol A waxy, fat-like substance made in the liver and in certain foods, and found in the blood and in all cells of the body. It is a factor in the development of atherosclerosis
Chondromalacia Patella Softening of the articular cartilage of the kneecap
Chorea Involuntary uncontrolled uncoordinated movements
Choreiform Spasmodic writhing movements of limbs and facial muscles
Choroid The thin vascular (major blood vessel) layer of the eye between the retina and the sclera that covers the white of the eyeball responsible for supplying blood to the retina
Christmas Disease A rare disease of blood clotting, similar to haemophilia
Chromosome One of the 46 small bodies in the nucleus of cells, which carry genes. Also may be known as “genome”. An abnormality of chromosomes may cause conditions such as Down’s syndrome
Chronic Long-term or prolonged; applied to a disease that is not acute
Chronic Obstructive Pulmonary Disease (COPD) Chronic obstructive pulmonary disease (COPD) is a term for a group of disorders, which are chronic, progressive and characterised by difficulty in breathing. Terms such as chronic bronchitis, emphysema, chronic obstructive airways disease, chronic airflow limitation and some cases of chronic asthma are all known as COPD
Chronic suppurative otitis media (CSOM) A persistent inflammation of the middle ear and characterised by recurrent persistent discharge from the ear. The discharge usually occurs through a persistent perforation of the eardrum
Chronic Urticaria Hives or nettle rash. Defined as urticaria on most days for more than six weeks – usually no identifiable cause can be found.
Churg Strauss Syndrome A rare form of vasculitis. Churg-Strauss syndrome, in particular, occurs in patients with a history of asthma or allergy and features inflammation of blood vessels, also referred to as angiitis, in the lungs, skin, nerves, and abdomen
Cirrhosis A liver disorder in which the liver cells are destroyed and replaced by scar tissue. Its effects are very variable, ranging from few or no symptoms, to liver failure resulting in coma or death
Claudication Limping with pain in legs on walking; relieved by rest. Due to insufficient blood supply to the limb. This is normally caused by partial blockage of arteries by atherosclerosis (“hardening of the arteries”)
Claustrophobia Abnormal fear of enclosed places
Clavicle Two thin bones that join the scapula and the sternum (the collar bone)
Claw hammer toes Deformity of the toes
Cleft Palate Congenital fissure in the roof of the mouth due to failure of fusion before birth. The lip may also be affected (“cleft lip”)
Clonic Seizure A type of generalised seizure characterized by jerking movements and involving muscles on both sides of the body
Clot The end of a series of reactions that change liquid blood into a jellylike mass. Also known as a thrombus
Coccyx The final segment of the lower end of the vertebral column. Also known as the “tailbone”
Cochlea Spiral tube forming part of the inner ear, which is the essential organ of hearing. This tube is filled with tiny hair cells which help transmit sound into the brain
Cochlear Cochlear Implants are surgically implanted devices, which electrically stimulate the auditory nerve in the cochlea in response to sound
Coeliac disease An autoimmune disorder due to exposure to gluten (found in cereals) characterised by damage to all or part of the villi lining the small intestine
Cognitive Relating to knowing understanding and reasoning; logical thought processes
Cognitive Behaviour Therapy A form of psychotherapy that teaches the patient to recognise and challenge automatic negative thought patterns. The aim is to enable the patient to counter the negative thought with alternative rational thoughts. E.g. In back pain CBT challenges the negative thoughts that pain is harmful and exercise makes the problem worse
Colitis Inflammation of the lining of the large bowel (or colon) and rectum
Collagen The fibrous protein costituent of bone, cartilage, tendon and other connective tissue
Colon The greater part of the large bowel
Colostomy The diversion of faeces through an opening in the colon, creating a surgical opening on to the abdominal wall
Coma A state of profound unconsciousness in which there is total unresponsiveness
Community Mental Health Team (CMHT) A team that supports people with mental health problems in the community. CMHT members include community psychiatric nurses (CPN), social workers, psychologists, occupational therapists, psychiatrists and support workers
Community psychiatric nurse (CPN) A nurse who specialises in mental health, and has received further training to enable them to work in the community where they will assess and treat people with mental health problems
Compulsion An uncontrollable impulse to perform an act, often repetitively, as an unconscious mechanism to avoid unacceptable ideas and desires which, by themselves, arouse anxiety
Co-Morbid A concomitant but unrelated pathological or disease process
Complex Partial A seizure that affects a larger part of the brain and the person is no longer aware of their surroundings and they may loose consciousness. They may wander about, fumble with clothes, babble to themselves or make other noises- known as automatism. The seizure is often preceded by a simple partial seizure (aura, or warning)
Compression The act of pressing upon or together; the state of being pressed together e.g. compression of vertebrae in the spine
Computed Tomography (CT) or CAT Scan X-Ray technique that provides a cross-sectional image of any area of the body
Concave Curving Inward
Concussion Traumatic Injury to the brain that may result in abrupt, temporary loss of consciousness
Conductive Deafness Hearing loss or impairment caused by a defect in part of the ear that conducts sound, specifically the external canal or middle ear
Cones Colour-sensitive nerve endings in retina
Congenital A condition that is present at the time of birth
Congestion The presence of an abnormal amount of fluid in a vessel or organ, especially excessive accumulation of blood
Conjuntiva The delicate covering of the eyeball
Conjunctivitis Inflammation of the conjunctiva, the delicate covering of the eyeball
Constipation Infrequent or difficult defaecation with hard stools caused by decreased movements of the gut
Contraindication A symptom or medical condition that makes a particular treatment or procedure inadvisable because a person is likely to have a bad reaction. For example, having a bleeding disorder is a contraindication for taking aspirin because treatment with aspirin may cause excess bleeding
Contralateral On the opposite side of the body
Contracture A permanent shortening of the muscles and tendons adjacent to a joint, which can result from severe, untreated spasticity and interferes with normal movement around the affected joint
Convex Curving outward
Convulsion Violent, involuntary contraction and jerking of muscles. Also known as seizure
Cornea Clear part of the eye covering the iris and pupil - lets light into the eye, permitting sight
Coronary Angioplasty (PTCA) A procedure in which a balloon-tipped catheter is inserted usually via the femoral (groin) artery and manoevered into the narrow heart artery. The balloon is then inflated to stretch the vessel opening and improve blood flow through it
Coronary Artery Bypass Graft (CABG) An operation in which a section of vein or artery is used to bypass a blockage in a coronary artery; performed to prevent myocardial infarction (heart attack) and to relieve angina
Coronary Artery Disease A condition in which the heart muscle receives inadequate blood due to narrowing or obstruction of the coronary arteries causing angina and heart attacks
Cor Pulmonale Acute strain or hypertrophy of the right ventricle caused by a disorder of the lungs or of the pulmonary blood vessels. Leads to oedema
Cortical Refers to the outer layer of the brain, the cortex
Cortical Blindness Loss of vision resulting from a lesion of the primary visual areas of the cortex. Light reflex is preserved
Corticosteroids A drug (steroid) used clinically to suppress inflammation of the tissues and to suppress the immune response
Cortisone A naturally occurring corticosteroid that functions primarily in carbohydrate metabolism
Costochondritis A painful swelling of a rib in the region of the chest, over the junction of bone and cartilage
Crepitus A grating sound and sensation created when two rough surfaces in the human body come into contact - for example, in osteoarthritic joints or fractured bones rub together
Crescendo pain Rapidly progressive pain
Cryotherapy A method of stunting the growth of tissues by freezing them
Cryptogenic Of obscure or unknown origin. Used of diseases
Cued Speech A method of communication that combines speech reading with a system of handshapes placed near the mouth to help deaf or hard-of-hearing individuals differentiate words that look similar on the lips
Curative treatment Treatment intended to cure disease
Cushing’s Disease Cushing's Syndrome is a condition caused by an excess of steroid hormones called cortisol
Cutaneous Relating to the skin
Cyanosis Blue or purple discolouration of the lips and nails, due to reduced amount of oxygen in blood
Cyclo oxygenase (COX) An enzyme existing in two forms, called COX-1 and COX-2. COX enzymes are responsible for the production of prostaglandins, intracellular messengers found at high levels at inflammation sites
Cyst A sac lined by body tissue, normally filled with fluid or semi solid material
Cystitis Inflammation of the urinary bladder
Cystectomy Surgical removal of all or part of the urinary bladder.
Cystoscopy Direct visual examination of the inside of the bladder through the urethra by means of a tube and lens system
Cytology The study of cells
Cytomegalovirus A very common virus that can cause serious disease in people with low resistance to infection. It can cause a variety of clinical symptoms including deafness or hearing impairment; infection with the virus may be either before or after birth
Cytotoxic Drug A drug, which is toxic to, and kills cells (e.g. Used in malignant disease to destroy cancer cells)

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D

Term Description
Debility Weakness, loss of power and strength
Decubitus Ulcer Bedsore; pressure sore
Defaecation Discharge of faeces from the body
Degeneration/Degenerative A gradual deterioration in structure with resultant impairment of function. (For example, macular degeneration in the eye)
Dehydration Excessive loss of water from the body
Delerium A state of mental confusion marked by disorientation and hallucination. Fever and certain drugs are common causes
Deletion syndrome Deletion syndrome is a rare genetic syndrome affecting chromosome 22. It has very variable features. Individuals may have one or more of the following at birth: congenital heart disease, cleft palate, reduced immunity to infection, blood disorders or hearing loss. Affected children are at higher risk of ADHD and developmental and learning disorders. The functional effect of these conditions may be mild, moderate or severe.
Delusion A false belief, entirely without foundation
Dementia The loss of intellectual functions (such as thinking, remembering, and reasoning) of sufficient severity to interfere with a person’s daily functioning
Depot injection
An injected anti-psychotic or other drug, which is released over a period of several weeks. Medication is given in this way to people who may be unable to take oral medication on daily basis
Depersonalisation (Derealisation) The experience of feelings of loss of a sense of reality. The person feels that they have changed and the world has become less real, they are divorced from both the world and from their own identity and physicality. Often times the person who has experienced this disorder claims that life "feels like a movie, things seem unreal
Depression A mental state of depressed mood characterized by feelings of sadness, despair and discouragement
DeQuervain's syndrome An inflammation of the sheath or tunnel that surrounds two tendons that control movement of the thumb
Dermatitis A skin rash characterized by itching, swelling, blistering, oozing and scaling of the skin
Dermatology Medical speciality involving the study of skin and its diseases
Desensitisation therapy (Graded exposure therapy) A technique used in behaviour therapy to treat Phobias and other behaviour problems involving anxiety; by exposure to the threatening situation under relaxed conditions until the anxiety reaction is extinguished
Desiccated Loss of fluid, dried out
Detached retina Visual impairment resulting from the retina becoming separated from the choroid in the back of the eye. Click here for more details about Vision. Click here for more details about Diabetes Mellitus
Diabetes mellitus A chronic metabolic disease caused by failure of the pancreas to produce insulin, a hormone that allows blood sugar (glucose) to be taken up by cells that require it for function. People with diabetes often need to follow a strict diet and may require insulin injections. During a diabetic reaction, a person may experience confusion, sudden personality changes, or loss of consciousness. In extreme cases, diabetes can also cause vision loss, cardiovascular disease, kidney failure, stroke, or necessitate the amputation of limbs
Diagnosis Indentifying the condition causing an illness or disability from signs and symptoms by clinical examination and laboratory tests, etc
Diaphragm The musculomembranous partition separating the abdominal and thoracic cavities and serving as a major muscle aiding inspiration
Diastolic blood pressure The second of two numbers used to measure blood pressure. This is the minimum pressure in the arteries between beats when the heart relaxes to fill with blood
Diffuse Widespread, not limited to one tissue or location
Diffuse Parenchymal Lung Disease This term describes a group of over 200 diseases of various causes, which result in scarring around the air sacs (alveoli) of the lung. The scar tissue reduces oxygen transport from the air into the blood, which makes breathing harder work. The main symptom is breathlessness on exercise. In severe cases, there may be breathlessness at rest. Formerly known as Interstitial Lung Disease
Digestion The mechanical and chemical breakdown of food to simple substances that can be absorbed from the gut into the body
Dilatation The process of enlargement or expansion
Diplopia Double vision
Disc Disease Degeneration/prolapse of the discs, which separate the bones of the vertebral column. It is a cause of pain in the back
Disc Prolapse A disc that bulges out from its position between two vertebrae
Disease Activity Score (DAS) An assessment used in Rheumatoid arthritis which measures disease activity. The score range is from 0-10; a score of less than 3.2 means the disease is inactive and a score of more than 5.2 very active. It should be noted that this score is not always a good measure of disability
Disease-modifying anti- rheumatic drugs (DMARD) Drugs used to treat inflammatory conditions, such as rheumatoid arthritis, by slowing the disease process and preventing damage
Disinhibition Inability to suppress impulsive behaviour and emotions
Dislocation Displacement of a bone from a joint
Dispensing Optician A dispensing optician is trained to dispense spectacles and has expertise in ophthalmic lenses
Dissection Division, separation, or removal of tissues
Dissociative The segregation of a group of mental processes from the rest of a person's usually integrated functions of consciousness, memory, perception, and sensory and motor behaviour
Distensible That which can be distended (swollen out or expanded)
Diuretic A drug that increases the production of urine
Dopamine A neurotransmitter in the brain
Doppler A diagnostic tool that uses low intensity ultrasound to detect blood flow velocity in arteries or veins
Dorsiflexion Bending the foot and toes in the direction of the upper surfaceBending the foot and toes in the direction of the upper surface
Down’s syndrome A syndrome caused by a chromosome abnormality. It is characterised by slowed growth, abnormal facial features and learning difficulties. Possible related health problems include poor resistance to infection, hearing loss, gastrointestinal problems, and heart defects
Drepanocytosis (Sickle-cell) A hereditary blood disease mainly affecting people of African ancestry
Dumping Syndrome A condition associated with the rapid emptying of gastric contents into the small intestine causing flushing, sweating, dizziness and weakness. Often occurs after surgery on stomachand duodenum
Duodenum The first part of the small intestine into which the stomach drains
Dupuytren's contracture Localised thickening of the tissues of the palm of the hand, causing progressive flexion (bending towards the palm) of one or more fingers. Surgery may be needed to release the thickened tissue
Dysarthria A group of speech disorders caused by disturbances in the strength or coordination of the muscles of the speech mechanism as a result of damage to the brain or nerves
Dysfunction Absence of normal function
Dyslexia Difficulty in reading or learning to read, accompanied by difficulty in writing and spelling correctly
Dysmenorrhoea Painful menstruation (periods)
Dyspepsia Indigestion
Dysphagia Difficulty in swallowing
Dysphasia Difficulty in understanding or using spoken or written language due to brain damage
Dysplasia Abnormally formed tissues, organs or cells often due to chronic irritation or inflammation
Dysphonia Any impairment of the voice or difficulty speaking
Dyspnoea Difficulty in breathing resulting in shortness of breath. It is often associated with heart or lung disease
Dyspraxia Partial loss of ability to perform coordinated movements
Dysrhythmia An abnormal heart rhythm
Dystonia A neurological movement disorder in which there is prolonged muscle contraction affecting one or more parts of the body, resulting in repetitive twisting movements or abnormal postures; it includes such conditions as torticollis and writer's cramp
Dysuria Painful urination
Dysthymia A chronic low-grade depressive disorder

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E

Term Description
E-test A chart used for testing vision and visual acuity
Echocardiogram A test that uses ultrasound waves to measure the size of the heart and its chambers. It shows whether the heart is beating normally and the valves of the heart are working properly
Echolalia The repetition of speech just spoken by somebody else in an involuntary and meaningless way. People with echolalia may repeat a word, phrase, or entire sentences. Also known as echologia, echophasia, echophrasia, echo speech and mimic speech
Ectopic Out of place. An ectopic heart beat originates in an abnormal location of the heart. Ectopic pregnancy is a foetus developing outside the uterus
Eczema A skin rash characterized by itching, scaling, swelling, blistering, and oozing of the skin
Efficacy The ability of a drug to produce the desired therapeutic effect
Effusion The accumulation of fluid, or the fluid itself, in various spaces in the body. Commonly, the knee has an effusion (swelling) after an injury
Electrocardiogram (ECG) A recording of the electrical changes that accompany the beating of the heart. Often used to diagnose heart disease
Electro-convulsive therapy (ECT) A procedure in which an electric current is briefly applied to produce a seizure, primarily used in the treatment of severe affective disorders, depression and schizophrenia
Electroencephalogram (EEG) A recording of electrical impulses of the brain to diagnose certain diseases (such as epilepsy)
Electrolyte One of the substances in the blood and bodily fluids 'salts' in the blood (such as sodium and potassium)
Electromyography (EMG) Evaluation of the electrical activity of resting and contracting muscle to ascertain causes of muscular weakness, paralysis and involuntary movements of muscles
Embolic Stroke A type of ischaemic stroke where the blood clot forms in another part of the body, most commonly in the heart due to turbulent blood flow in a heart chamber. The clot then becomes dislodged and travels in the bloodstream until it becomes stuck in an artery in the brain, blocking the blood flow. This free roaming clot is called an embolus
Embolism Obstruction or closure of a blood vessel by an embolus [i.e. a blood clot; bubble of air, mass of bacteria or other debris]
Emesis Vomiting
Emphysema Distension or hyperinflation of the tiny air sacs (alveoli) and small air passages (bronchioles) due to loss of elasticity. It can accompany chronic respiratory diseases (such as chronic bronchitis), and causes breathlessness. It is a chronic respiratory disease
Encephalitis An inflammation of the brain, but it usually refers to brain inflammation caused by a virus
Encephalopathy Any degenerative brain disease
Endemic goitre A type of goitre,where a whole community or population may have a high incidence due to dietary iodine deficiency
Endocarditis Inflammation of the lining of the heart cavity and valves
Endocrine Relating to the secretion of hormones. The endocrine system consists of various glands which produce hormones
Endocrine Gland An organ that produces hormones and secretes them out into the bloodstream
Endometriosis A condition in which patches of endometrium occur in parts of the body other than the womb
Endometrium The lining of the womb
Endogenous A form of depression not triggered by life events
Endoscope An illuminated tube with lenses used to look inside hollow organs (i.e. the stomach; urinary bladder)
Enuresis Bedwetting in children
Enuretic alarm An apparatus used in the treatment of bed wetting in children. When urine comes into contact with a pad placed under the bed sheet an alarm bell rings to waken the child
Enzyme A substance, which can increase the speed of chemical reactions. Enzymes are involved in all the metabolic activities, which take place within body cells
Epidemic A disease that affects many individuals in a population at the same time
Epidemiology Medical science concerned with the occurrence and distribution of disease in human populations
Epidural An injection of an anaesthetic substance into the epidural space of the spinal cord in order to produce epidural anaesthesia of the lower body
Epilepsy A disorder of brain function characterised by recurrent seizures
Episodic Memory This is the event-based memory unique to each individual
Epstein-Barr Virus A herpes virus that is the causative agent of infectious mononucleosis. It is also called EB virus
Erythema Abnormal skin redness often a sign of inflammation or infection
Erythrocyte Red blood cell
Erythrocyte Sedimentation Rate (ESR) The erythrocyte sedimentation rate (ESR), or sedimentation rate (sed rate), is a measure of the settling of red blood cells in a tube of blood during one hour. The rate is raised in infections, autoimmune conditions and some malignancies
Erythropoietin A hormone that stimulates red blood cell production
Euphoria A feeling of great happiness and well-being
Eustachian Tube The tube that connects the middle ear and the back of the nose, draining the middle ear and regulating air pressure
Euthymic A psychological state, which is neither elated or depressed
Euthyroid Normal thyroid function
Exacerbation An increase in the severity of symptoms or of disease
Executive Function A term used to refer to aspects of higher order brain function, such as problem solving, reasoning and mental abstraction. These functions are located in the frontal lobes
Exercise Test A test where the patient walks at increasing speed and incline. The patient's heart rate and ECG is monitored throughout the test. Sometimes called the Bruce Protocol Test. Click here for more information on the Bruce Protocol Test
Exophthalmos Bulging of the eyeball. It may be a symptom of thyrotoxicosis
Expiration The process by which the lungs expel air; also called exhalation
Expressive Refers to how information - thoughts and feelings - is expressed
External Located on or near the surface of the body
Extra- pyramidal side effects Parkinson like symptoms (tremors etc.) caused by certain drugs
Extrasystoles The term used to describe a short sequence of extra heartbeats (premature contractions)
Extrinsic Of or relating to an organ or structure, originating outside the part where it is found or upon which it acts
Extrinsic Allergic Alveolitis This is a type of Diffuse Parenchymal Lung Disease with an allergic cause, also known as Hypersensitivity Pneumonitis. Examples include Farmer's Lung caused by allergic sensitivity to dust from mouldy hay, Bird Fancier's Lung and Metal Worker's Lung. Some cases may be prescribed diseases when occupationally exposed as an employed earner to such agents. Exposure causes inflammation in sensitised individuals, which may lead to scarring. See Diffuse Parenchymal Lung Disease
Exudate A fluid with a high concentration of protein and cellular debris, which has escaped from blood vessels and has been deposited in tissues, or on tissue surfaces, usually as a result of inflammation

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F

Term Description
Factors VIII & IX Substances present in blood, which are essential for normal blood clotting. Lack of Factor VIII causes classical haemophilia, (Haemophilia A), and lack of Factor IX, Haemophilia B or Christmas disease
Facet joint Joints between two adjacent vertebrae. Each vertebra is connected at the inter-vertebral disc in the front and the two facet joints in the back
Fainting Fainting (‘Syncope’) is a transient loss of consciousness with a resultant loss of postural tone caused by a temporary interruption of blood flow to the brain
Familial Tending to occur repeatedly in family members but is not genetic (inherited). Might indicate susceptibility, or a common environmental influence
Febrile
Feverish
Femur The bone that extends from the pelvis (hip) to the knee, being the longest and largest bone in the body (known as the thigh bone)
Festinating Gait Rapid, short shuffling steps seen in Parkinson's disease
FEV1
(Forced Expiratory Volume)
This is the amount of air that can be exhaled in the first second after taking the deepest breath possible. In obstructive lung disease, this measurement is as basic as taking temperature. Asthmatics who take their FEV1 with a peak flow meter on a daily basis can tell when an attack is beginning before the person even feels symptoms
Fibrillation Involuntary brief contraction of a muscle; also atrial fibrillation
Fibrin A protein, which forms the basis of a blood clot
Fibromyalgia A condition, which affects the muscles and ligaments but does not damage the joints. It is a common condition and can be severe. In fibromyalgia the fibrous tissues (fibro-) and muscles (-my) are affected by pain (-algia) and tenderness. Fatigue is often the most severe aspect of fibromyalgia
Fibrosing alveolitis Also known as Interstitial pulmonary fibrosis. A condition in which the tiny air sacs and adjacent lung tissue becomes inflamed, thickened and inelastic, causing progressive breathlessness on exertion
Fibrosis The formation of fibrous tissue as a reparative or reactive process
Fibrositis Pain and stiffness in and around muscles and joints, which may be due to local Inflammation. It is an example of soft tissue rheumatism
Fine Motor Skill Small precise movements usually of the hands. Vision is usually involved but you can have Fine Motor Skill even if blind
Finger counting A rough test of vision by holding up fingers at a designated distance and asking the visually impaired person to say how many fingers can be seen
Fistula An abnormal passage between two organs or between an internal body cavity and the outside (e.g. arterio-venous fistula: a connecting passage between an artery and vein)
Fixed flexion deformity Inability to fully straighten bend, move a limb
Flaccid Relaxed, flabby, or soft; or lacking muscle tone
Flexion The act of bending (as opposed to extending) a joint
Floaters Particles that float in the vitreous and cast shadows on the retina; seen as spots, cobwebs, spiders, etc. Occurs normally with aging or with vitreous detachment, retinal tears, or inflammation
Focus The origin or centre of a disseminated disease
Forced Vital Capacity (FVC) The amount of (volume) of air exhaled when the person is breathing out with maximum effort
Fovea A depression in the retina that contains only cones (not rods), and that provides acute eyesight
Fowler’s surgery An operation for RA in which the toe joints are removed leaving the toes to fuse
Fracture Any break in a bone
Fragile X Syndrome Inherited disorder characterized by learning difficulties and physical abnormalities
Fronto Temporal Dementia A dementia related to either frontal or temporal lobe degeneration. Click here for more information about Fronto Temporal dementia
Frozen Shoulder Pain and stiffness at the shoulder due to damage and inflammation of the soft tissues around the shoulder joint. Also known as Adhesive Capsulitis
Fulminant Occurring suddenly with great intensity

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G

Term Description
Gait The way in which a person walks
Galactosaemia An inherited metabolic disorder characterised by the deficiency of an enzyme necessary for galactose metabolism and characterised by elevated levels of galactose in the blood and, if untreated, mental retardation and eye and liver abnormalities
Gallbladder A small pouch that stores and concentrates bile, located under the liver
Gallstones Stones in the gallbladder
Gangrene Death and rotting of tissue
Gastrectomy Surgical removal of part or all of the stomach
Gastro - enteritis Inflammation of the stomach and intestine causing vomiting, diarrhoea and cramping, often caused by bacteria or viruses
Gastroenterology The medical speciality that deals with diagnosis and treatment of diseases of the digestive system
Gastrointestinal Relating to the stomach and the intestines
Gastrointestinal (GI) tract (Also called: Alimentary Canal.) A continuous tube running from the mouth to the anus
Gastro-oesophageal Reflux Disease (GORD) Occurs when acidic gastric contents escape from the stomach and irritate and inflame the lining of the oesophagus
Gastroscopy Examination of the interior of the stomach with an illuminated tube and lenses
Gene The basic unit of heredity, which is present in the chromosome. It carries information, which determines the physical and mental makeup of the individual
Genetic Hereditary
Genetics The study of heredity
Genitalia Reproductive organs
Geriatrics Branch of medicine devoted to the medical problems and care of elderly persons
Gilbert's disease Jaundice without evidence of liver damage, biliary obstruction, or hemolysis due to a harmless enzyme deficiency
Gilles de la Tourette Syndrome A rare condition in which affected people have involuntary repetitive twitching movements, and facial grimaces and make repeated sudden explosive noises, including the involuntary uttering of swear words. This is commonly known as Tourette Syndrome
Glandular Fever Glandular fever, also called infectious mononucleosis, is a viral infection caused by the Epstein-Barr virus
Glaucoma An eye disorder in which there is increased pressure within the eyeball, which can lead to impaired vision and blindness
Glenohumeral joint The ball-and-socket joint between the arm and the shoulder
Glucagon A hormone produced by the pancreas, which increases the level of glucose in the blood
Glucose A simple sugar; the major source of energy for every cell type in the body
Glycaemia Glucose content in the blood
Glycogen storage disease Any of a number of rare inborn errors of metabolism caused by defects in specific enzymes or transporters involved in the metabolism of glycogen
Glycogen The chief carbohydrate storage material in animals stored primarily in liver and muscle and synthesised and metabolised for energy as demanded
Glycosuria The presence of glucose in the urine, which is usually an abnormal finding
Goldenhars syndrome A congenital syndrome involving multiple malformations of the mouth, eyes and ears. The heart, kidneys, or nervous system may be affected
Golfers Elbow A condition characterised by pain at the outer side of the elbow especially when moving it against a resistance
Gout A disease in which there is an excessive amount of uric acid in the blood, which gets into joints and causes severe inflammation, pain and swelling
Graded Exposure Therapy (Desensitisation Therapy) A technique used in behaviour therapy to treat phobias and other behavioural problems involving anxiety; by exposure to the threatening situation under relaxed conditions until the anxiety reaction is extinguished
Grand Mal An older term for a tonic-clonic seizure- a type of generalized seizure. These seizures are characterized by a loss of consciousness with stiffening of the body and jerking body movements
Grandiose In psychiatry, pertaining to exaggerated belief or claims of one's importance or identity, often manifested by delusions of great wealth, power, or fame
Graves' Disease An auto-immune disease in which the body’s immune system produces antibodies, which stimulate the thyroid gland. The gland responds by producing an excessive amount of hormone and goitre can result from the massive over-activity of glandular tissue. It may also cause build up of tissue behind the eyes, which causes them to protrude (exophthalmus)
Grommet A tube surgically implanted in the eardrum to drain fluid from the middle ear
Guillain-Barre Syndrome A neurologic syndrome, usually following certain virus infections, marked by paresthesia of the limbs and by muscular weakness or a flaccid paralysis
Gynaecology
The study and treatment of disorders of the female reproductive system

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H

Term Description
HAART Highly active antiretroviral therapy (HAART) is a treatment for human immunodeficiency virus (HIV) infection that uses a combination of several antiretroviral drugs. The drugs inhibit the ability of the virus to multiply in the body, and they slow down the development of AIDS. Since the introduction of HAART, AIDS dementia complex has become uncommon
Haematemesis The vomiting of blood.
Haematology
The study of blood- forming organs
Haematoma A swelling filled with blood
Haematuria Blood in the urine, which may indicate urinary tract disease
Haemochromatosis An hereditary disorder of iron metabolism characterised by excessive accumulation of iron in tissues, diabetes mellitus, liver dysfunction and a bronze skin pigmentation
Haemodialysis Filtering of blood by an artificial kidney apparatus that removes waste material from the blood, which is returned to the body, in cases of kidney failure
Haemoglobin The red-coloured iron-protein molecule in red blood cells which carries oxygen around the body
Haemophilia A familial (inherited) disease characterized by delayed or entire absence of blood clotting
Haemoptysis Coughing up blood
Haemorrhage An escape of blood from a ruptured blood vessel
Haemorrhagic stroke A stroke caused by a damaged or weakened artery which has burst and bled into the surrounding brain tissue. This not only reduces the blood supply to more distant parts of the brain, it also upsets the delicate chemical balance the neurones require in order to function
Haemostasis Arrest of bleeding
Hallucination A false perception of something that does not really exist. A sensory experience created from within the brain, which may be perceived as a smell, or taste, or vision or feeling that has no basis in the external world
Hallux rigidus Osteoarthritis of the big toe joint with a fixed, rigid toe
Hallus valgus Osteoarthritis of the big toe joint, where the joint at the base of the toe projects outwards and the top of the toe turns inwards
Hammer toes Deformity of the toes
Hashimoto's Thyroiditis An inflammatory disease of the thyroid glandular tissue and impairs the ability to produce thyroid hormones. The gland becomes enlarged as a result of the inflammation
Heart Attack Myocardial Infarction; Coronary Thrombosis. The death of heart muscle due to an insufficient blood supply, [caused by a blocked coronary artery]
Heartburn Burning sensation in the gullet or oesophagus due to acid rising up from the stomach
Heart Failure Heart or cardiac failure occurs when the pumping action of the heart is inadequate and fails to maintain proper circulation
Heart murmur An abnormal sound due to the flow of blood across heart valves. It may indicate heart disease
Heberden’s nodes Small, bony nodules (spurs) found in the finger joints in osteoarthritis
Hemianaesthesia Loss of sensation of the affected part
Hemianopia Loss of one half of the visual field
Hemiarthroplasty Arthroplasty in which one joint surface is replaced with an artificial material
Hemicolectomy Removal of half of the large intestine (colon) by surgery
Hemicrania Affecting one side of the head
Hemiplegia Paralysis of the upper limb, trunk and lower limb on one side of the body [mild hemiplegia is known as hemiparesis]
Hepatic Encephalopathy A condition, occurring secondary to advanced liver disease, marked by disturbances of consciousness that may progress to deep coma (hepatic coma), psychiatric changes of varying degree and a flapping tremor
Hepatitis Inflammation of the liver due to virus, drugs, or chemical poisons
Hepatocyte A liver cell
Hepatoma Primary liver cancer
Hepato-cellular Relating to or affecting liver cells
Hepato-toxic Damaging or destructive to the liver
Hereditary Transmitted from parent to child by information contained in the genes
Hernia A rupture; the protrusion or projection of an organ or part of an organ from its normal position. e.g. inguina (groin hernia),hiatus hernia
Herpes An inflammatory disease of the skin or mucous membranes with blistering due to infection by a virus (Herpes Simplex causes "cold sore"; Herpes Zoster causes “shingles”)
Hiatus Hernia A protrusion of part of the stomach through the diaphragm into the chest
Hila The root of an organ through which nerves, ducts, or blood vessels enter and leave in an organ or a gland
Histrionic A behavior characterized by an excitable nature and the constant desire for stimulation
Hypnotic An agent that causes sleep
Histamine A naturally occurring substance, which is released in inflammatory processes, and allergic reactions
Histopathology The science concerned with the cytologic and histologic structure of abnormal or diseased tissue
Hive (Weal) A transient swelling, confined to a small area of the skin, that is characteristic of urticaria
HIV Positive A blood test which indicates that the person has been infected by the Human Immunodeficiency Virus (HIV virus) which infects the cells in the human immune system
Hodgkin's lymphoma One of a group of malignant conditions of lymphoid tissue
Holter Monitor A Holter Monitor or 24 hour ambulatory ECG, is a test which, continually records the electrical activity of the heart over a 24 hour period
Homeopathy A system of medicine based upon the principle that "like cures like". Homeopathic medication given in extremely small doses which can produce symptoms of the disease to be cured, in order to stimulate the body’s defence (immune) system
Homeostasis Automatic self-regulation to maintain the normal or standard state of the body
Homonymous hemianopia Defective vision or blindness in the right or left halves of the visual fields of both eyes. This is a frequent condition in people who have had a stroke
Hormone A chemical messenger produced by a body organ and carried by the blood to another organ/tissue where it influences function, structure and activity. E.g. insulin thyroxin
Housemaid's knee Inflammation of, and fluid formation in the pouch (bursa) at the front of the knee joint, often caused by kneeling
Human Immune Deficiency Virus (HIV) The causative organism in AIDS
Human papilloma virus A virus that causes common warts of the hands and feet, as well as lesions in the genital and vaginal area. More than 50 types of HPV have been identified, some of which are linked to cancerous and precancerous conditions, including cancer of the cervix
Humerus The long bone in the arm, which extends from the shoulder to the elbow
Humidifier An apparatus for increasing the moisture in the air of a room
Hydrocele (also Hydrocoele) A swelling caused by accumulation of fluid, especially around the testicle
Hydrocephalus Too much cerebrospinal fluid in the ventricles in the brain, leading to pressure on the brain and enlargement of the skull
Hydrocortisone A hormone produced by the adrenal gland, which affects the handling of sugar and protein by the body. Its synthetic counterpart is used in treating severe allergic reactions, skin disorders such as eczema, and diseases such as rheumatoid arthritis and bronchial asthma
Hydrotherapy Rehabilitation exercises performed in water
Hyperaesthesia Excessive sensitiveness to touch
Hyperalgesia Excessive sensitivity to pain
Hypercalcemia Hypercalcemia is an abnormally high level of calcium in the blood
Hypercholesterolaemia Excess cholesterol in the blood
Hyperglycaemia Excess of sugar in the blood, usually associated with diabetes
Hyper-inflate Excessively or abnormally inflated e.g. hyper-inflated chest (barrel-chested)
Hyperlipidemia Excess levels of fats in the blood
Hypermetropia Long sightedness (or farsightedness). Distance vision is good, near vision is blurred
Hypermotility Excessive movement (usually used with reference to the bowel or joints)
Hyperosmolar Relating to the abnormal increase in the osmole content of a solution, especially a body fluid
Hypersomnolence Excessive sleeping or sleepiness. Also called Hypersomnia.
Hyperplasia Excessive formation of normal tissue, which increases in size
Hypersensitivity Responding excessively to the stimulus of a foreign agent, such as an allergen; abnormally sensitive
Hypertension High blood pressure
Hyperthermia An abnormally high body temperature. This is a serious medical emergency that requires immediate hospitalisation. Body temperatures above 40°C (104°F) are considered life-threatening
Hyperthyroidism (Thyrotoxicosis) Excessive activity of the thyroid gland causing an excessive production of thyroid hormone which in turn raises the metabolic rate leading to weight loss, rapid pulse, excessive sweating, irritability and intolerance of the heat
Hypertrophy An increase in size of a tissue or organ
Hyperuricaemia High levels of uric acid in the blood
Hyperventilation Over-breathing which, by affecting the chemical balance of the blood, can cause transient feelings of light-headedness or faintness
Hypervigilance Abnormally increased arousal, responsiveness to stimuli, and scanning of the environment for threats
Hypnotherapy The use of hypnosis in psychotherapy
Hypnotic That which produces hypnosis or sleep, in this context referring to a drug inducing sleep
Hypocalcaemia Abnormally low level of calcium in the blood; associated with hypoparathyroidism or kidney malfunction or vitamin D deficiency
Hypochondria A morbid preoccupation or anxiety about one's health
Hypochondriasis A persistent belief in the presence of at least one serious physical illness despite negative physical findings and reassurance
Hypoglycaemia A condition in which the blood-sugar level is below normal. E.g. a complication of insulin treatment
Hypoglycaemic drugs Agents, which lower sugar in the blood. Used in treating some forms of diabetes mellitus
Hypokinesia Decreased muscular activity
Hypomania A degree of elation, over activity and excitement greater than normal but less than mania
Hypopituitarism A deficiency of one or more hormones of the pituitary gland. The pituitary produces a number of hormones which regulate other hormone glands e.g. thyroid
Hypoplasia Imperfect development or underdevelopment of an organ or tissue
Hypotension An abnormally low blood pressure
Hypothalamus A small structure at the base of the brain that controls many body functions, including appetite and body temperature and regulates the pituitary gland
Hypothermia A severe reduction in body temperature
Hypothyroidism (Myxoedema) Reduced activity of the thyroid gland
Hypotonia Reduced muscle tone, floppy
Hypoxaemia An insufficient oxygen content in the blood
Hypoxia A state of oxygen deficiency in the tissues
Hysterectomy Surgical removal of the uterus (womb)

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Term Description
Iatrogenic Brought about by medical or surgical treatment
Icterus Jaundice
Ictus
A sudden attack (usually used to refer to a seizure or fit). Post-ictal: following a fit
Idiocy
Very severe arrested development causing profound learning difficulties
Idiopathic Applied to a condition for which the medical cause has not yet been established
Idiosyncrasy A peculiarity of constitution, temperament or behaviour
Idiosyncratic A distinctive characteristic of a thing
Ileocaecal valve The junction between the terminal ileum and the caecum or first part of the colon
Ileostomy An operation to make an opening connecting the lower end of the small intestine (ileum) through the abdominal wall to the outside of the body. This opening is called a stoma; and intestinal contents can be discharged into a small bag, which fits tightly over the stoma
Illusion A mistaken sensory perception; believing something to be what it is not (e.g. seeing a person in shadows)
IMED pump An automatic pump for delivering intravenous fluids into the body at a steady rate
Immune Protected against a particular infection
Immunity The resisting power of the body to invading micro-organisms
Immunoglobulin An antibody. A protein found in blood and tissue fluids, produced in response to a specific antigen
Immunological Of or relating to the body's immune system
Immunosuppressive drug A drug, which suppresses the normal immune mechanisms in the body. Used to permit successful organ grafting (as in kidney or heart transplants), and in some diseases with an autoimmune basis such as rheumatoid arthritis and ulcerative colitis
Imperforate Without an opening
Implantable Cardioverter Defibrillator (ICD) An ICD is a surgically inserted electronic device that constantly monitors the heart rate and rhythm. When it detects a very fast, abnormal heart rhythm (ventricular fibrillation or tachycardia), it delivers an electrical shock to the heart muscle. This causes the heart to beat in a normal rhythm again
Impotence Inability of a man to have or maintain an erection sufficient for sexual intercourse
Incidence The extent or rate of occurrence, especially the number of new cases of a disease in a population over a period of time
Incoordination A lack of coordination of movements
Incubation The development of an infectious disease from the entrance of the pathogen to the appearance of clinical symptoms
Incus The center bone of the series of three small bones, or ossicles, of the middle ear. Sometimes called the anvil
Indigestion Pain or discomfort in the lower chest or abdomen after eating
Inertia Remaining at rest, lack of movement
Infarct An area of death (necrosis) in an organ or tissue produced by lack of oxygen resulting from the blocking of its blood supply
Infarction The formation of an infarct (i.e. myocardial infarction: death of the heart muscle following a coronary thrombosis
Infection Invasion of the body by micro-organisms, which cause disease
Infectious Mononucleosis Infectious mononucleosis also called Glandular fever, is a viral infection caused by the Epstein-Barr virus
Inflammation A series of changes in tissues indicating their reaction to injury, whether mechanical, chemical or bacterial. The cardinal signs are: heat, swelling, pain and redness
Inflammatory Disease A disease characterized by inflammation
Infusion A slow injection of a fluid, into a vein
Ingestion The taking in and swallowing of food, drink and other things such as medicines by mouth
Inhalation The breathing into the lungs through the nose and mouth of air, gas or vapour
Inhaler A device used for administering medication directly into the lungs. It is most often used in the treatment of asthma
Inheritance The acquisition of qualities and characteristics (genetic material) from parents and ancestors
Innervation Nerve supply to a part.
Innocuous Harmless
Insidious Of subtle, gradual, or imperceptible development; referring to the development of symptoms that may not be recognized by an affected individual until the disorder in question is established
Insight Mental awareness, perception, understanding
Insomnia Difficulty falling or staying asleep or poor sleep quality
Insulin A hormone secreted by the pancreas, which regulates the handling of sugars and fats by the body. A lack of, deficiency of, or resistance to this hormone causes diabetes mellitus. Click here for more information about diabetes
Intelligence Quota (IQ) A psychometric test used to assess intelligence. The average IQ is 100. IQs of 70 and over are considered normal
Intermittent Claudication Pain in the muscles of the legs (usually the calves) and limping on walking, due to a decreased blood supply to the lower limbs. It is relieved by rest
Interphalangeal Between the bones of the fingers or toes
Inter-vertebral disc Cartilage (cushion/pad) that separates spinal vertebrae. It absorbs shocks to the spine, protects the nervous system and assists in creating the four normal curves of the spine
Intra Cranial Within the skull. Usually refers to the brain
Intractable Difficult to manage/control
Intramuscular Within the muscular substance
Intraocular Of or related to the inside of the eye
Intrathecal Within the thecal sheath. See Theca
Intravenous Within or by means into a vein; e.g. "intravenous feeding" or " intravenous injection."
Intrinsic Situated within or belonging solely to the organ or body part on which it acts
Ion An atom or a group of atoms that has acquired a net electric charge by gaining or losing one or more electrons
Ionizing radiation Radioactive waves or particles that can ionise other molecules including DNA
Ipsilateral Occurring on the same side. Applied particularly to paralysis or other symptoms occurring on the same side of the body
Iridotomy A surgical (laser) procedure that makes an incision in the iris of the eye in order to enlarge the pupil or to treat glaucoma
Iris Coloured part of the eye that is in fact a diaphragm opening and shutting to let in more or less light into the eye
Iritis Inflammation of the iris, the coloured part of the eye surrounding the pupil
Iron chelating drug A compound that binds with iron to assist its removal from the body (See Chelating Drug)
Irrational Not consistent with or using reason; "irrational fears"
Irritable Bowel Syndrome (IBS) A disorder of unknown cause of the alimentary tract, causing small and/or large bowel dysfunction associated with abdominal pain and an altered bowel habit
Ischaemia A deficiency in the blood supply to a part of the body, thereby depriving it of oxygen
Ischaemic Heart Disease (IHD) Ischaemic Heart Disease (Coronary Artery Disease or CAD) is a condition in which atheroma (fatty deposits) builds up in the linings of the walls of the coronary arteries
Ischaemic Stroke The commonest form of stroke. It occurs when an artery supplying a part of the brain with blood becomes blocked causing a sudden reduction or complete cessation of blood flow. This will ultimately lead to a brain infarction
Isometric Having equal dimensions. Used to describe exercises known as "isometric exercises" which is the contraction and relaxation of muscles without producing movement
Isthmus A strip of tissue that connects two larger parts of the thyroid gland
(IVP) Intravenous Pyelography An x-ray examination of the kidneys ureters and bladder following the intravenous injection of a radio-opaque dye

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Term Description
Jacksonian Epilepsy A form of epilepsy in which there are localised convulsive movements, and there is no alteration of awareness. Also known as Focal Motor Seizures
Jaundice A yellowish pigmentation of the skin, eyes, tissues and certain body fluids caused by the build up of bile pigments that follows excretion of bile (as in certain liver diseases). Click here for more details about Jaundice.
Jejunostomy The making of an opening into the jejunum (small gut) through the abdominal wall, through which food may be introduced into the small intestine
Jejunum The portion of the small intestine (small gut) from the duodenum to the ileum
Joint capsule The thin, cartilaginous, fatty, fibrous, membranous structure that envelops a joint. Fluid inside the joint capsule lubricates the area, allowing bones to glide smoothly against each other
Joint Laxity Lack of stability of a joint or joint prosthesis
Juxta-articular Near a joint

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Term Description
Keratitis Inflammation of the cornea
Keller’s surgery
This is an operation performed to correct hallux valgus (bunions)
Ketoacidosis Acidity of the blood caused by the increased production of ketone bodies, as in diabetic acidosis
Ketogenic diet A specialised high-fat, low-carbohydrate diet sometimes used to control epilepsy
Ketone An organic compound, which is produced by the breakdown of fats in the body such as occurs in uncontrolled diabetes (ketoacidosis)
Ketonuria The presence of ketones in urine. This can be a sign of undiagnosed or uncontrolled diabetes mellitus
Kleptomania An impulse control disorder distinguished by an uncontrollable urge to steal typically unnecessary objects
Klinefelter's syndrome A chromosomal abnormality in males, who are born with an additional X chromosome
Korsakov's Syndrome Also known as Korsakov’s Psychosis. A confusional state due to thiamine (vitamin) deficiency causing brain damage in severe chronic alcoholism
Kyphoscoliosis An abnormal curvature of the spine in which there is both sideways curvature and forward humping of the upper part of the spine
Kyphosis A curvature of the spine causing a hump back

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Term Description
Labile Unstable
Labyrinthitis A condition, usually the result of a viral infection, of the labyrinth, in the inner ear. It results in vertigo and tinnitus
Lacrimal (Lachrymal) Relating to tears. For example, the lachrymal glands secrete tears
Lacrimal (Lachrymal) glands Paired glands, one for each eye, that secrete lacrimal fluid (tears)
Lactate To secrete or produce milk
Laminectomy Surgical removal of part of a vertebra. Usually done to relieve pressure on a spinal nerve caused by a herniated disk or bony spur
Laparoscopy
Viewing of the abdominal cavity by passing a thin illuminated telescope (Laparoscope) through a small Incision in the abdominal wall. (Laparotomy)
Laryngectomy Excision of part or all of the larynx (voice box) and a section of the trachea (windpipe), usually because of cancer. A permanent stoma (opening) is created at the front of the throat, for breathing
Larynx
The organ of the voice, situated at the upper end of the windpipe. It is also known as the voice box. Across it are spread the vocal cords; the vibrations and contractions of which produce changes in the pitch of the voice
Laser Light Amplification by Stimulated Emission of Radiation. An apparatus producing an extremely concentrated beam of light that can be used as a surgical tool. Used, for example, in the treatment of cancer, of detached retina, diabetic retinopathy and in the treatment of certain skin conditions
Lateral Situated at the side of the body
Laxity Slackness or displacement in the motion of a joint
Learning Disability Includes the presence of: - a significantly reduced ability to, understand new or complex information and learn new skills [impaired intelligence] with a reduced ability to cope independently [impaired social functioning], which started before adulthood with a lasting effect on development
Lens Nearly spherical body in eye - focuses light rays onto retina
Leptospirosis Any of a group of infectious diseases that are caused by spirochetes of the genus Leptospira, are characterised by jaundice and fever and are transmitted to humans by contact with the urine of infected animals
Lesion Injury, wound, or changes due to disease in an organ. A local disease condition
Leukaemia The generic name for a group of acute and chronic malignant diseases of bone marrow and blood forming organs
Libido A person's sex drive
Ligament A band of fibrous tissue that connects bone to bone or cartilage to bone, supporting or strengthening a joint
Ligamentous Laxity Looseness of the ligaments
Limbic System The limbic system is a group of connected structures in the mid brain area that are responsible for emotions and memory
Lipoma A tumour of fat cells usually just under the skin
Liver The largest organ in the body situated in the right upper area of the abdominal cavity. Its chief functions are: (1) The secretion of bile, which aids the digestion of food (2) The removal of toxins, medications and waste products from the blood (which may damage the liver in the process) (3) The storage of fat and sugar (4) Synthesis of plasma protein, and other important metabolic processes. It is essential to life
Liver Failure This is the name given to the clinical state in which there is damage to the hepatocytes (liver cells) to the extent that the function of the liver is measurably impaired. Click here for details of Liver Failure
Lobectomy Surgical removal of one lobe (section) of an organ, usually the lung, but it may be the liver, brain, etc
Lobar Emphysema Overinflation of one of the upper lobes of a lung with respiratory distress, usually occurring in early life
Locomotor Related to movement from one place to another
Lordosis A form of spinal curvature. A forward curve the opposite of kyphosis
Lucid Clear, particularly of the mind
Lumbago An imprecise term for pain in the lower part of the back
Lumbo-sacral Of or relating to or near the small of the back (lumbar vertebrae) and the back part of the pelvis between the hips (sacrum)
Luminance Perceived brightness, or grayscale level, of a colour
Lyme disease An infection resulting from a tick bite affecting the heart, nervous system, and joints
Lymph The almost colourless fluid, which bathes the tissues, and supplies nutrients to tissue cells
Lymph Node Lymph nodes/glands are small rounded or bean-shaped masses of lymphatic tissue found throughout the body. They help to fight infection and become enlarged and tender when an infection is present e.g. enlarged neck glands in tonsilitis
Lymphatic system Small vessels that drain tissue fluid back into the veins
Lymphocyte A white blood cell formed in the lymphoid tissue. Lymphocytes produce immune bodies (antibodies) to overcome and protect against infection
Lymphoedema Swelling, especially in subcutaneous tissues, as a result of obstruction of lymphatic vessels or lymph nodes, with accumulation of lymph fluid in the affected region
Lymphoma Used to denote any malignant condition of the lymphoid tissue. Generally these diseases are classified as either Hodgkin's or non- Hodgkin's lymphomas

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Term Description
Macrocephalic Possessing an abnormally large head
Macrophages White blood cells whose job is to destroy invading microorganisms
Macroscopic Discernable to the naked eye
Macula A flat spot or discoloured area of the skin. The most sensitive region of the retina used for reading
Macula Degeneration A medical condition where the light sensing cells in the macula malfunction and over time cease to work causing difficulty with tasks such as reading
Magnetic resonance Imaging (MRI) A form of medical imaging which gives computerised pictures of slices through the body at various levels, similar to those obtained by a CAT scan. It is non- invasive, and uses magnetic energy to detect the different resonances of atoms in tissues to different induced magnetic fields
Makaton A system of communication based on a combination of spoken words, sign language vocabulary (originally adapted from British Sign Language), and graphic symbols. It is primarily used as a communication medium by children and adults with learning disabilities. Unlike British Sign Language Makaton does not suffer from regional variations or dialects
Malabsorption Inability of the small intestine to absorb certain nutrient substances
Maladaptive Unsuitable or counterproductive e.g. maladaptive behaviour is behaviour that is inappropriate to a given situation
Malformation A structural defect
Malaise
A feeling of general discomfort and not feeling right. It may be the first indication of many illnesses
Malignant A term applied to any disease of a virulent and fatal nature; but often used to describe cancerous tumours or cancer
Malignant melanoma A type of cancer affecting the melanin-forming cells. Melanin is the natural pigment that colours hair, skin and eyes. Malignant melanomas most commonly occur in the skin
Malleus The first bone in the series of three small bones, or ossicles, of the middle ear. Sometimes called the hammer
Malnutrician Poor nutrition because of an insufficient or poorly balanced diet or faulty digestion or metabolism of foods
Mammography X-ray examination of the breasts for diagnostic purposes
Mania Elevation of the mood to the point of extreme elation accompanied by acceleration of thought and action, impaired judgement and often by delusions of grandeur. Psychotic features may be present. It is usually part of Bipolar Disorder
Manometer An instrument which measures pressure
Marrow The soft, fatty substance contained inside certain bones. It is a major source of blood cell production
Mastectomy  
Mastoiditis A condition, which occurs due to infection of the membranes of the mastoid air cells with formation of pus within the cavities and inflammation of the surrounding tissue and bone
Maximal Being the greatest or highest possible
Mechanical back pain Also known as non-specific back pain. Although the pain may be in the spinal joints, vertebrae or soft tissues in the vast majority of cases it is not possible to identify a pathologically definable problem
Melaena The discharge of black faeces [stained with blood which has undergone change] after bleeding into the gastro intestinal tract
Melancholia A state of extreme depression
Melanoma A type of malignancy affecting the skin
Meniere's Disease or Syndrome A disease of the inner ear causing attacks of giddiness (sensation of rotation) and tinnitus (ringing in the ears) with progressive deafness
Meninges The three membranes covering the brain and spinal cord
Meningitis Inflammation of the meninges usually due to viral or bacterial infection
Meningoencephalitis Inflammation of the brain and meninges
Meningomyelocele A protrusion of the spinal cord, nerve roots and meninges through a defect in the vertebral back bone. (See also: Spina bifida.)
Meniscectomy Surgical removal of all or part of a torn cartilage in a knee joint
Meniscus/Menisci (Cartilage) Free rings of cartilage, like washers, lying between the cartilage- covered bones in the knee, acting as extra shock absorbers; each knee has an inside (medial) and outside (lateral) meniscus
Menopause The normal cessation of menstruation in women usually occurring between the late 40’s and early 50’s. There is an associated reduction in female hormone production, which may cause symptoms such as night sweats, hot flushes, irritability, depression and other symptoms
Menorrhagia Excessive menstrual bleeding
Menstruation The monthly discharge of blood and endometrium (womb lining) from the uterus (womb), starting at the age of puberty and lasting until the menopause
Mental Health Act Legislation for the medical care and protection of people who are mentally ill. The Mental Health Act also ensures the rights of patients who are involuntarily admitted to hospital. Click here for more information about Section of the Mental Health Act and other Orders.
Metabolic Having to do with metabolism (the total of all chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes)
Metabolism The use of foods by the body following digestion, absorption and circulation to the body cells. Foods are used both as an energy source and, after being broken down chemically during digestion, as basic materials for making complex chemical compounds required by the body. These processes are necessary for life
Metabolite Any product of metabolism, or of a metabolic process
Metacarpo-phalangeal (MCP) Knuckle joint between the metacarpals (hand bones) and the phalanges (finger bones)
Metatarsal Relating to the bones of the foot
Metatarso-phalangeal (MTP) Joint between the metatarsals (foot bones) and the phalanges (the toe bones)
Metaplasia Abnormal change in the structure of a tissue. May be indicative of malignant change
Metastases Tumour cells spread from one part of the body to another unrelated part of the body by the way of the bloodstream or lymphatics
Metastasis The transfer of cancer from one part of the body to another through the blood vessels, via the lymph channels or across the body cavity. The resultant tumours are known as “secondary tumours” or “secondaries”
Metatarsalgia A painful foot condition in the metatarsal region of the foot
Microalbuminuria A very small increase in urinary albumin. May indicate kidney damage.
Micro-aneurysms Small protuberances on the retinal blood vessels. The first sign of eye damage caused by many years of high blood glucose levels
Microbe A minute living organism, especially one causing disease
Microcephalic Having an abnormally small head, in which the prognosis for normal brain function is poor
Micro Discectomy Also known as micro decompression spine surgery, a small portion of the bone or disc material around the nerve root is removed to relieve pressure on the nerve
Micrognathia Failure of development of the lower jaw, causing a receding chin. It may be associated with a number of syndromes, and in the infant, may pose considerable feeding difficulties
Micrographia Abnormally small, cramped handwriting and/or the progression to continually smaller handwriting
Micro-organism A minute (too small to be seen with the naked eye) organism, particularly a virus, bacterium, a fungus, or a protozoan
Micturition The act of passing urine
Middle Ear Implant Middle Ear Implants are surgically implanted devices, which mechanically assist sound transmission into the inner ear and replace the 3 small bones in the middle ear.
Migraine Paroxysmal (recurrent) attacks of severe headache, often with nausea, vomiting and visual disturbance
Milestone One of the "checkpoints" against which the motor, social and psychological development of a child is measured
Mitral stenosis A condition in which the mitral valve in the heart becomes narrowed, making the heart work harder to pump blood; can lead to symptoms such as shortness of breath
Mitral valve A valve of the heart between the left atrium and left ventricle
Mixed Deafness Hearing loss comprising of both conductive and sensorineural elements
Monarticular Involving one joint only
Monoclonal Derived from a single cell
Monocular Refers to only one eye
Monoplegia Paralysis of one limb or of a single muscle or a group of muscles
Monotherapy Treatment of a condition by means of a single drug
Mood stabilising drugs Drugs that control mood
Morbid Diseased, or relating to an abnormal or disordered condition
Morbidity A figure that shows the susceptibility of a population to certain diseases. Usually shown as the number of cases, which occur annually per thousand or other unit of population. Also: a diseased condition or state
Moribund In a dying condition
Motor Something that causes movement. (E.g. Motor nerve is one of the nerves, which conveys an impulse from a nerve centre to a muscle to promote activity)
Motor Neurone Disease A disease, which affects the motor neurons conveying impulses from the central nervous system to a muscle, gland, or other effector tissue resulting in conditions such as progressive muscular atrophy, amyotrophic lateral sclerosis, progressive bulbar paralysis and primary lateral sclerosis
Motor skills The ability to perform purposeful movements. Fine motor skills are those, which involve small movements such as writing, tying laces, and making crafts. Gross motor skills are those involving large movements and include walking, running, riding a bike, and playing ball
MRI Scan A form of medical imaging which gives computerised pictures of slices through the body at various levels, similar to those obtained by a CAT scan. It is non- invasive, and uses magnetic energy to detect the different resonances of atoms in tissues to different induced magnetic fields
Mucous Relating to or secreting mucus. (E.g. mucous membrane: a membrane that secretes mucus and lines many of the body cavities, particularly those of the respiratory and intestinal tracts.)
Mucoviscidosis Another name for cystic fibrosis or fibocystic disease, a congenital disease, which affects the lungs, sweat glands, and digestive system
Mucus The thick, slippery secretion of mucous membranes. Its function is to clean, lubricate and protect
Multidisciplinary team A group of people with different kinds of training and experience working together, usually on an ongoing basis. Professionals often use the word "discipline" to mean a "field of study," such as medicine, social work, or education
Multiple myeloma/myeloma A form of cancer that affects plasma cells which are special white blood cells that produce antibodies, the agents our bodies use to help fight infection. The disease can cause tumours to grow in bones leading to bone pain and fractures
Murmur A sound heard on listening to the heart, usually originating in the heart itself and is usually due to the turbulence of blood flow through diseased/abnormal heart valves
Mutate To alter or change
Myalgia Pain in the muscles
Myasthenia Muscle weakness. Myaesthenia Gravis is a disease characterised by weakness and fatigue of voluntary muscles of the body, which worsens with activity
Mycobacterium Avium Complex (MAC) Systemic disease caused by infection with organisms of the Mycobacterium avium-intracellulare complex in patients with human immunodeficiency virus infection (HIV)
Myelitis Inflammation of the spinal cord
Myelography X-ray examination of the structures within the spinal column such as the spinal cord and nerve roots, following the injection of a substance (radio- opaque dye), which shows up on x-rays, into the space, which surrounds the spinal cord
Myeloid Relating to, or of the bone marrow
Myeloma/multiple myeloma A form of cancer that affects plasma cells which are special white blood cells that produce antibodies, the agents our bodies use to help fight infection. The disease can cause tumours to grow in bones leading to bone pain and fractures
Myeloproliferative disorders A collective term for a group of malignant disorders in which there is overproduction of red blood cells, white blood cells or platelets in the bone marrow
Myocarditis Inflammation of the heart muscle. It is generally due to bacterial or viral infection
Myocardium The muscle tissue of the heart
Myoclonic Seizure A type of generalised seizure in which the person may jerk and twitch but will not lose consciousness
Myoclonus Involuntary jerky movements of the arms and legs
Myopathy Any disease of the muscles
Myopia Short sightedness. Also known as “nearsightedness”. It is a condition in which there is blurred vision of distant objects
Myopic Nearsighted, shortsighted: unable to see distant objects clearly
Myositis Inflammation of muscle tissue
Myotonia Problems relaxing muscles after contraction
Myringoplasty Surgical repair of a damaged tympanic membrane
Myringotomy Incision of the eardrum to drain fluid or pus from an infected middle ear
Myxoedema (Hypothyroidism) Reduced activity of the thyroid gland causing swelling of the face, limbs and hands, dry and rough skin, loss of hair, slow pulse, subnormal temperature, slow metabolism and mental dullness

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Term Description
Naevus A birthmark: A usually benign, pigmented area of the skin, or a patch of discolouration, or a vascular birthmark due to dilated capillaries and which can give the skin a reddish, purplish colour
Narcissistic A psychological condition characterised by self-preoccupation, lack of empathy, and unconscious deficits in self-esteem
Narcolepsy A condition, which is often familial in which there are recurrent, sudden bouts of irresistible sleep. The affected person will usually experience one other of the following: - cataplexy (sudden loss of muscle tone, sleep paralysis (brief paralysis on waking), and hypnagogic hallucinations (hallucinations experienced during waking or when going off to sleep)
Narcotic
A potentially addictive drug that produces a state of unconsciousness or unnatural sleep. Narcotic drugs are potent painkillers
Nausea Any sensation of sickness with an urge to vomit
Nebulizer An apparatus for reducing a liquid to a fine spray for inhalation. It is used in medicine to treat respiratory diseases (such as an acute asthma attack)
Necrosis Death of a portion of tissue
Negative symptoms These occur where there is a loss from a person’s usual behaviour such as: emotional bluntness, marked withdrawal, and difficulty in communicating with others, profound apathy, inability to cope with every day tasks
Neonatal Referring to the first month of life
Neoplasm A new growth; a tumour. It may be malignant or benign
Nephrectomy Surgical removal of a kidney
Nephritis Inflammation of one or both kidneys
Nephropathy Disease of the kidneys
Nerve root compression Harmful pressure on nerves. E.g. as they exit from the spinal cord causing nerve damage and muscle weakness or in carpel tunnel syndrome
Neuralgia A sharp stabbing pain, usually along the course of a nerve, owing to inflammation of the nerve or some other disturbance
Neurasthenia An old- fashioned term for a condition in which there is much mental and physical fatigue, inability to concentrate, loss of appetite and a failure of memory
Neuritis Inflammation of a nerve with pain, tenderness and loss of function
Neuro-degenerative Irreversible deterioration of essential cell and tissue components of the nervous system, causing problems with movements and or affecting memory
Neuroleptic Drugs Tranquilising drugs, especially those used in treating mental disorders
Neurological To do with the nerves or the nervous system
Neurologist One who is an expert in the diagnosis and treatment of diseases of the nervous system
Neurogenic intermittent claudication Leg and buttock pain when standing for long periods of time or when walking with the back in an extended position. It is due to nerve root compression
Neurology The scientific study of the nervous system, and its disorders
Neuromuscular Affecting both nerves and muscles
Neurosurgery Surgery of the nervous system
Neurone A nerve cell, that transmits signals to different parts of the brain
Neuropathy A disease process of nerve degeneration and loss of function
Neurotoxicity A substance that is poisonous or destructive to nerve tissue
Neurotransmitter Dopamine A chemical which transmits impulses between neurones
Nihilistic delusion A delusion that things(or everything, including the self)does not exist; a sense that everything is unreal
Nocturia The requirement to pass urine at night, causing the person to wake up to do so
Nodal osteoarthritis A form of osteoarthritis that runs in families, characterised by knobbly finger swellings (Heberden's nodes) and a tendency to get OA at several sites (especially knees, big toes)
Non compos mentis (Latin) Applied to a person whose mental state is such that he is unable to manage his own affairs
Non Epileptic Attack Disorder (NEAD) Non-Epileptic Attack Disorder (NEAD) has symptoms similar to epilepsy in that it causes loss of control, shaking and sometimes unconsciousness. However, there is no epileptic seizure (abnormal discharge of neurone in the brain
Non-Hodgkins Lymphoma Any of various malignant lymphomas characterised by the absence of Reed-Sternberg cells and producing symptoms similar to those of Hodgkin's disease
Non specific back pain Also known as Mechanical back pain. Although the pain may be in the spinal joints, vertebrae or soft tissues in the vast majority of cases it is not possible to identify a pathologically definable problem
Non Steroid Anti- Inflammatory Drugs (NSAID) Drugs that decrease fever, swelling, pain, and redness
Noxious Harmful or injurious
Nucleus The essential part of a cell, governing its nutrition and reproduction (containing DNA), its division being essential for formation of new cells
Nucleus Pulposus Soft centre of an inter-vertebral disc, made up of gel-like substance that gives the disc its shock absorbing quality. It is kept in place by the Annular ring (annulus). The Intradiscal Fluid keeps the Nucleus Pulposus from drying out
Nystagmus An involuntary rapid movement of one or both eyes. It may be in a horizontal, or vertical direction, or rotatory. It may indicate disease of the inner ear or of the central nervous system, or blindness from a very early age

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O

Term Description
Obese Having excessive fat in the body and having a Body Mass Index of 30. The body Mass Index is the figure reached at when the weight in kilograms is divided by height in meters squared
Obsession An idea, which persistently recurs to an individual, although he resists it and regards it as being senseless
Obsessive Compulsive Disorder (OCD) A mental illness characterised by obsessive thoughts that causes anxiety. This leads to rituals or repetitive actions e.g.constantly washing hands, to relieve the anxiety
Occipital Relating to the occiput, that is, the back of the head
Occiput The back of the head
Occlusion Closure, applied particularly to alignment of the teeth; complete blockage of arteries
Occult Hidden, concealed, such as bleeding - (“occult blood in the stools”)
Ocular Relating to the eye
Oedema An excessive amount of fluid in the body tissues causing swelling
Oesophagitis Occurs when acidic gastric contents escape from the stomach and irritate and inflame the lining of the oesophagus
Oesophagus The part of the alimentary canal, which extends from the pharynx to the stomach. Known as the gullet
Oestrogen Female steroid sex hormones that are secreted by the ovary and responsible for typical female sexual characteristics
Olfactory Relating to the sense of smell
Oncology A scientific study of tumours and tumour- related diseases
Oophorectomy Removal of one or both ovaries
Opacity Something that reduces the passage of light often used to describe cataracts (opacity of lens.)
Ophthalmologist A medical doctor trained in the examination, diagnosis, management and treatment (including surgery) of most eye conditions
Ophthalmoplegia Paralysis of one or more of the eye muscles
Ophthalmoscope An instrument containing a perforated mirror and lenses used to examine the interior of the eye
Opiate Any medication containing opium. E.g. morphine
Optic Relating to vision
Optic chiasma The crossing of the optic nerves from the two eyes at the base of the brain
Optic disc The small blind spot on the surface of the retina where cells of the retina converge to form the optic nerve; the only part of the retina that is insensitive to light
Optician An optician is a person who reads prescriptions given by ophthalmologists and optometrists for vision correction, orders lens and dispenses glasses and contact lenses
Optic Nerve The nerve that carries images from the retina to the brain
Optic Neuritis Inflammation of the optic nerve. Characterized by rapid onset of decreased vision and usually accompanied by discomfort upon eye movement and central visual field defect
Optometrist A health professional trained to detect and correct refractive errors, to examine, detect and diagnose eye conditions
Orbit The cavity or socket of the skull in which the eye and its appendages are situated
Organ of Corti The sensitive organ of hearing within the cochlear duct. The organ of Corti contains specialised cells called hair cells that convert sound vibrations into electrica nerve impulses
Organic Having properties relating to living organisms. Relating to the organs. (E.g. organic disease: disease of an organ, accompanied by structural changes.)
Organism An individual living being, animal or vegetable
Orthopaedics The branch of medicine dealing with the study and surgical treatment of deformities, injuries and diseases of the bones, joints, tendons and muscles
Orthoptist An orthoptist is a person who assesses vision and eye movements. They can assess squints and patients complaining of double vision. They usually work in eye clinics with ophthalmologists
Orthosis A device that is used to protect, support, or improve function of parts of the body that move e.g. a brace or splint. Orthoses is plural
Orthotic An appliance promoting the straightening and support of a deformed or distorted part of the body, such as a limb
Os A bone. A mouth or mouth like opening
Ossicle A small bone such as those in the middle ear
Osteitis Inflammation of bone
Osteo Arthritis Osteo-arthritis (OA) is a disease of the joints characterised by cartilage destruction and new bone formation. Click here for more details about Generalised Osteo-arthritis
Osteochondritis Inflammation of bone and cartilage
Osteomalacia A disease characterised by painful softening of bones. Due to vitamin D deficiency in adults. Also known as “Adult Rickets”
Osteomyelitis Inflammation of a bone due to infection
Osteopathy A system of therapy that emphasizes normal body mechanics and manipulation to correct faulty body structures. It is considered a complementary medicine
Osteophyte Bony outgrowth (seen on X-ray) at joint margin of an osteoarthritic joint, or in degenerative disc disease also known as 'lipping' or 'spurs'
Osteopaenia A condition of bone in which there is a generalised reduction in bone mass that is less severe than that in osteoporosis
Osteoporosis A common bone disease characterised by reduced bone mass and thinning of internal bone structure. This leads to an increased risk of fractures especially neck of femur, wrist and collapse of vertebrae
Osteosarcoma A malignant bone tumour occurring in young adults
Otolaryngology The scientific study of the ears nose and throat, and the diseases affecting them
Otosclerosis A hearing condition in which the stapes in the ear becomes attached to the surrounding bone by an abnormal bone growth. Sound transmission is progressively impaired so that hearing in the affected ear deteriorates

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P

Term Description
Pacemaker
An electrical device, which stimulates the heart muscle to contract and controls heart
Paediatrics The branch of medicine dealing with the care and development of children and the diagnosis, treatment and prevention of children's diseases
Paget's disease A chronic disease of bone caused by increased bone turnover, which produces bone pain enlargement, deformity, and weakness
Pain Clinic A clinic, usually run by anaesthnetists, to treat the physical aspects of pain
Pain Management Clinic Run by a professional multi - disciplinary team, usually consisting of a psychologist, physiotherapist, nurse and doctor. Treats people who have chronic pain of at least 6 months duration and where all other appropriate treatments have been undertaken. Click here for more details about Pain Management Clinic.
Palliative Treatment, which relieves, but does not cure disease. Often used in reference to treatments for terminal cancer
Palmar Erythema Redness of palms and hands due to inflammation
Pallor Extreme or unnatural paleness
Palpation The method of examination of the organs by touch or pressure of the hand over the surface of the body. The size, shape, mobility of internal organs can be assessed this way
Palpitation Rapid and forceful contraction of the heart of which the person is aware
Palsy Paralysis
Pancreas An organ situated behind the stomach which produces 1) hormones (insulin and glucagon) which regulate blood sugar levels, and 2) digestive enzymes which drain into the small intestine, and which help with digestion
Papilloedema Swelling of the optic nerve at the back of the eye normally caused by an increase of pressure within the skull
Paradoxical That which is apparently, though not actually, inconsistent with or opposed to the known facts in any case
Paraesthesia An abnormal tingling sensation (i.e. "pins and needles")
Paralysis Loss of the power of movement of any part, as a result of an interference with the nerve supply
Paramedic Someone trained to assist nurses and doctors, and trained to administer emergency treatment, (such as ambulance crew)
Paramedical Having some association with the science of practice of medicine
Paranoia A mental disorder characterised by ongoing suspicion, mistrust, hostility and delusions of persecution
Paraparesis An incomplete paralysis affecting the lower limbs
Paraphrenia Schizophrenia and paranoid state occurring for the first time in later life
Paraplegia Paralysis of the lower extremities and lower trunk. All parts below the point of the injury to the spinal cord are affected. It may be of sudden onset from injury to the cord or may develop slowly as a result of disease
Parasite Any animal or vegetable organism living upon or within another (host) from which it derives its nourishment
Paraspinal muscles The muscles next to the spine
Parasympathetic One of two types of nerves of the autonomic nervous system responsible for controlling functions which take place at the unconscious level, for example digestion, slowing the heart rate, regulating blood pressure, constricting the pupils of the eyes
Parenteral Referring to the introduction to the body of drugs or fluids by routes other than the mouth or rectum, for instance intravenously (through a vein) or subcutaneously (through the skin)
Paresis Partial paralysis
Parietal lobe An area located in the uppermost section of the brain. Important in processing information about temperature, taste, touch and movement
Paroxysm A sudden attack, spasm or seizure or recurrence of a symptom or of a disease. It may also mean convulsion
Pathogen A micro-organism such as a virus or a bacterium which can cause disease
Pathognomonic Specifically characteristic of a disease
Pathological anxiety A disproportionately excessive level of anxiety that interferes with the ability to function in normal daily activities
Pathology The branch of medicine concerned with the study of disease processes and mechanisms, and the effect on the body
Peak Flow Meter A small hand-held device that measures how fast air comes out of the lungs when a person exhales forcefully. Click here for more details about Peak Flow
Peak Expiratory Flow Reading (PEFR) Measurement of lung airways obstruction
Peak Flow Test A test to measure lung airways obstruction
Pelvic inflammatory disease (PID) A general term for a condition that involves infection and inflammation of the upper female genital tract, include the womb, fallopian tubes, and ovaries
Peptic Ulcer An ulcer in the lining of usually the stomach or the duodenum
Perception The process of acquiring, interpreting, selecting, and organizing sensory information
Percutaneous Through the skin
Percutaneous Transluminal Coronary Angioplasty (PTCA) A procedure in which a balloon-tipped catheter is inserted usually via the femoral (groin) artery and manoevered into the narrow heart artery. The balloon is then inflated to stretch the vessel opening and improve blood flow through it
Perfusion The passage of liquid through a tissue or an organ, particularly the passage of blood through the lung tissues, or through the skin tissues
Pericarditis Inflammation of the pericardium (the fibroserous sac enclosing the heart and the roots of the great vessels)
Perinatal Refers to the period around the time of birth
Perineum The region between the scrotum and the anus in males and between the posterior vulva junction and the anus in females
Peripheral Vascular Disease A narrowing of blood vessels that restricts blood flow to the limbs. It mostly occurs in the legs, but sometimes in the arms, causing loss of sensation in the extremities ( fingers and toes)
Peripheral Pertaining to or situated away from a centre or central structure i.e. at or near the periphery
Peripheral vision Side vision; seeing objects or movement to the side of the direction of gaze
Peritoneal Cavity The potential space between the parietal and visceral layers of the lining membrane of the abdominal cavity
Peritoneum The lining membrane of the abdominal cavity, which also covers some of the abdominal organs
Peritonitis Inflammation of the peritoneum usually due to infection
Permeability The degree to which a fluid can pass from one structure through a wall or membrane into another
Pernicious aneamia An anaemia due to lack of absorption of vitamin B12
Peritonitis Inflammation of the peritoneum, which may be due to chemical irritation or bacterial infection
Perthe’s disease (Avascular necrosis) A disorder characterised by the deterioration of the head of the femur in the hip joint, due to its insufficient blood supply
Pertussis Whooping Cough
Pessimism A belief that things are bad, and tend to become worse, a general disposition to look on the dark side and to expect the worst in all things
PET scanner A device that produces cross-sectional images after the injection of a radioactive substance of metabolic processes by means of positron emission tomography. Used to identify secondary spread of cancers
Petit mal Absence seizures. A form of epilepsy common in children and characterised by sudden and brief absences
Phalanges The bones of the fingers or toes
Pharynx The muscular tube lined with mucous membrane situated at the back of the mouth and nose. It leads to the gullet, and also communicates with the windpipe
Phenothiazines Are the largest of the 5 main classes of antipsychotic drugs. Although these drugs are generally effective, there are often serious side-effects (especially in the early stages of treatment)
Phenylketonuria also known as PKU This is an inherited abnormality in which phenylalanine cannot be broken down in the body. This can lead to severe mental deficiency if not detected and treated
Phenytoin An anticonvulsant drug used in some form of epilepsy (seizures)
Phlebitis Inflammation of a vein, usually in the leg
Phobia An irrational fear produced by a specific normal or harmless situation, which the person attempts to avoid. A common example is agoraphobia
Photophobia Excessive sensitivity to light
Photoreceptor A nerve end-organ or receptor sensitive to light
Photosensitivity/Photosensitisation An abnormal degree of sensitivity of the skin to sunlight. Some medications can increase this sensitivity
Physiological Relating to physiology; normal; not pathologic
Pigment The dye-like material in cells that provides colour to skin, eye and hair
Pinna (auricle) The external, visible portion of the ear. Its primary function is to carry sounds to the middle ear
Pituitary A hormone-secreting gland situated at the base of the brain. It secretes many different types of hormones which act in turn on many other glands and organs of the body
Placebo An inactive substance which when administered (under the impression that it is a drug) causes some improvement, which cannot be related to any particular effect of that substance
Placenta Organs that attach the developing embryos or foetus to the inside of the uterus. It links the mother's and foetus blood supply keeping them separate but allowing oxygen nutrients and some antibodies to cross. Some viruses may also cross the placenta
Plantar Relating to the sole of the foot
Plantar fasciitis Inflammation of the thick fibrous tissue of the sole of the foot causing chronic pain on walking
Plasma The yellow fluid part of the blood in which the blood cells are suspended
Plasma Viscosity A blood test identifying the degree of inflammation
Plasmapheresis A process in which plasma is taken from donated blood and the remaining components, mostly red blood cells, are returned to the donor
Platelet Disc-shaped structures found in blood concerned in the process of clotting. (Also known as a thrombocyte)
Pleural fibrosis The development of fibrous tissue in lung tissue
Pleurisy Inflammation of the lining of the lung, which causes a sharp pain in the chest on breathing
Plexopathy Any disorder of a network of veins, lymph vessels or nerves, especially the nerves
Plexus A network of veins, lymph vessels or nerves
Pneumococcal Pneumonia The most common type of acute bacterial pneumonia usually affecting one lung
Pneumococcus A bacterium (Streptococcus pneumoniae) that is the most common cause of bacterial pneumonia and is associated with meningitis and other infectious diseases
Pneumoconiosis Caused by the inhalation of mineral dusts such as coal and silica. Some cases may be prescribed diseases when occupationally exposed as an employed earner to such agents. See Diffuse Parenchymal Lung Disease
Pneumocystis A pneumonia caused by the parasitic protozoan Pneumocystis carinii and affecting primarily individuals with an immunodeficiency disease, such as AIDS
Pneumonectomy Total removal of a lung for example, for the treatment of cancer
Pneumonia Inflammation of the lung usually caused by an infection, which is accompanied by fever, coughing, breathlessness and pains in the chest
Pneumothorax Air or gas in the pleural space, usually as a result of trauma or some pathological process
Poliomyelitis (Infantile paralysis) This is the full name for the disease known as "polio", A viral infection causing damage to nerves in the spinal cord resulting in paralysis, weakness and wasting of muscle groups
Polyarthritis Inflammation of several joints at the same time, as seen in rheumatoid arthritis
Polycythaemia Too many red blood cells or "erythrocytes" in the blood
Polydipsia Excessive thirst. It may be a symptom of untreated diabetes mellitus
Polymyalgia Rheumatica A condition causing pain and stiffness in the muscles, usually involving the shoulder or hip region
Polyneuropathy Neuropathy of many peripheral nerves simultaneously
Polyuria Excessive urination; often-in conjunction with polydipsia
Port Access point to an indwelling catheter, enabling administration of drugs without gaining new access every time
Portal Hypertension Any increase in the portal vein (in the liver) pressure
Positive symptoms These occur when there is something added to a person’s thinking such hallucinations, delusion and disturbances in thought processes
Posterior Towards the back
Posterior Chamber Part of the eye behind the iris and in front of the lens
Posterior segment The part of the eye posterior (behind) to the crystalline lens, including the vitreous, choroid, retina and optic nerve
Posthumous Occurring after death
Post ictal The period after an epileptic seizure
Postmortem After death. (Postmortem examination or autopsy)
Postnatal Occurring after birth
Postpartum Occurring after labour (childbirth)
Postprandial Occurring after a meal
Post Seizure Manifestations A state of confusion, disorientation or impaired memory function usually following a tonic-clonic seizure. Other characteristics may be headaches, aggression, aching muscles, sore or tender tongue. This state may last for several hours or several days after a seizure
Postural Hypotension Low blood pressure occurring when standing up
Pott's Fracture A fracture dislocation of the ankle
Precancerous Applying to conditions or structural changes in tissues that run the risk of changing into cancer
Precipitating Factor A factor associated with a definitive onset of a disease, illness or behavioural response. E.g. Smoking is a precipitating factor in lung cancer
Predisposition The condition of having a genotype that increases the risk for developing a genetic disease, if triggered by other environmental conditions present. For example, some women have a family history of breast cancer and are therefore predisposed (but not necessarily destined) to develop breast cancer
Pre-eclampsia A condition of hypertension, oedema and proteinuria occurring during late pregnancy or immediately following pregnancy
Premenstrual The days preceding the onset of a menstrual period
Prenatal Before birth
Presbycusis Progressive deafness in old age
Presbyopia The gradual loss of the eye's ability to change focus from distance to near; occurs in almost everyone sometime after age 40
Prevalence The total number of cases of a disease in a given population at a specific time
Primary writing tremor (PWT) Primary writing tremor (PWT) is considered to be a type of task-specific tremor in which tremor predominantly occurs and interferes with handwriting
Proctalgia Pain in the rectum and/or anus (the lower end of the large bowel).
Proctocolectomy Surgical removal of the rectum and large bowel (colon)
Prodromal period Period of precursor symptom(s) indicative of the imminent onset of morbidity or disease
Productive Producing or capable of producing mucus or sputum
Prognosis A forecast of the course, duration and outcome of a disease
Progressive multifocal leucoencephalopathy (PML) A rare disease of the central nervous system resulting from destruction of the sheath which covers the nerves. It affects around 4% of people with AIDs but can be due to other viral infection
Proliferation Rapid multiplication of cells
Pronation Rotation of a body part (usually the hand or foot) downward
Prone Lying face downward
Prophylactic Measure or medication used to prevent disease
Prophylaxis Measures taken to prevent a disease
Proptosis Abnormal protuberance of the eyeball out of its socket
Prostaglandin One of several hormone substances produced in many body tissues. They have many different actions and are involved in the process of inflammation
Prostate A walnut-sized gland at the base of the bladder in the male, which produces fluid, which forms part of the semen. It often becomes enlarged after middle age and may require removal
Prostatectomy The surgical removal of part of the prostate gland. Radical prostatectomy is the removal of all the prostate
Prosthesis An artificial replacement for part of the body, such as artificial limbs, dentures eyes, breasts, pacemakers and artificial valves placed in the heart
Prosthetic heart valves Artificial surgically implanted replacements for diseased or damaged heart valves
Prostration A condition of extreme exhaustion
Protein One of a group of complex organic nitrogen-containing compounds formed from simpler substances known as aminoacids, and occurring in every living cell of animal and vegetable tissue
Proteinurina A condition in which protein is present in the urine. It may be an indicator of damage to the kidneys
Proton-pump inhibitors (PPI) Drug, which reduces acid secretion by the stomach
Protozoa A very diverse group comprising some 50,000 organisms that consist of one cell. Some cause disease
Proximal In anatomy, that part which is nearest to the centre of a body
Pruritus Irritation of the skin with itching
Pseudoclaudication Leg and buttock pain when standing for long periods of time or when walking with the back in an extended position
Psoriasis A chronic skin disease of unknown cause characterised by reddish spots with silvery scales
Psychiatry The branch of medicine, which deals with mental disorders, their diagnosis, treatment and prevention
Psychoactive drugs Drugs that affects the functioning of the mind and used to treat mental illness.
Pschodynamic A therapy technique that assumes improper or unwanted behaviour is caused by unconscious, internal conflicts and focuses on gaining insight into these motivations
Psychogenic A disorder of psychological origin.
Psychometrics The field of study (connected to psychology and statistics) concerned with the measurement of "psychological" aspects of a person such as knowledge, skills, abilities, or personality.
Psychomotor retardation A slowing down of thought and a reduction of physical movements in a person due to a mental illness.
Psychosis Symptoms of a mental illness comprising of delusions, hallucinations and thought processes
Psychosocial A term used to underline the close relationship between psychological and social effects of a person’s response to illness
Psychosomatic Relating to the mind and the body
Psychosomatic Disorders Illnesses when no physical cause can be found
Psychotherapy The treatment of mental and emotional disorders through the use of psychological techniques designed to encourage communication of conflicts and insight into problems, with the goal being personality growth and behavior modification
Psychotic A misinterpretation of the nature of reality. Typically hallucinations; delusional beliefs; disorders of the stream of thought (speed, pressure); formal thought disorder (linking of thoughts together).
Psychotropic Affecting the mind, emotions, or behaviour.
PTCA (Percutaneous Transluminal Coronary Angioplasty) A procedure in which a balloon-tipped catheter is inserted usually via the femoral (groin) artery and manoevered into the narrow heart artery. The balloon is then inflated to stretch the vessel opening and improve blood flow through it.
Ptosis Drooping of the upper eyelid.
Puberty The period during which the sexual characteristics develop and the reproductive organs become functional.
Puerperium A period of about six weeks following childbirth.
Pulmonary Relating to the lungs.
Pulmonary Function Test Any of several breathing tests that measure the function of the lungs, including the rate of air flow and the volume of exhaled air, performed to assess lung function and to detect the presence of respiratory disease
Pulmonary Oedema A severe state of increased interstitial fluid within the lung that leads to flooding of the alveoli with fluid
Pulmonary hypertension Abnormally increased blood pressure in the pulmonary circulation
Pulse The local rhythmic expansion of an artery which reflects the heartbeat, and which can be felt with the finger, in the wrist, neck, foot, and other places.
Pupil Round, dark centre of the eye - opens and closes to regulate the amount of light the retina receives.
Pus A yellow-white substance made by the body in reaction to an infection, composed of dead white blood cells, tissues and remains of bacteria.
Purulent Containing, discharging or causing the production of pus
Pyrexia Fever. Body temperature above 37 degrees Celsius

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Q

Term Description
Quadriceps A group of muscles in the front of the thigh that straighten the knee.
Quadriplegia (Tetraplegia) Paralysis of all four limbs.

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R

Term Description
Radioactivity The radiation, including alpha particles, nucleons, electrons, and gamma rays, emitted by a radioactive substance
Radioallergosorbent (RAST) test A RAST test ( radioallergosorbent test) is a blood test used to determine the sensitivity (allergy) of a person to certain substances. This is different from a skin allergy test, which determines allergy by the reaction of a person's skin to different substances
Radiograph An x-ray picture
Radiographer A person trained to take x-ray pictures
Radiologist A doctor specialising in the interpretation of x-rays (radiology)
Radiotherapy The treatment of disease (usually cancer) by x-rays/radiation
Radius One of the two forearm bones. The bone in the forearm on the same side as the thumb
Raynaud's Phenomenon Intermittent spasm of the small arteries usually of the hands, following exposure to cold or vibration. As a result, the fingers go white and numb. It may be part of a more serious and widespread rheumatic disorder
Receptive Language skills (listening and reading) that require the reader/listener to make sense of what he/she reads or hears
Rectum The lower part of the large intestine that ends at the anus.
Refactory Resistant to therapy
Reflex An automatic response to an outside stimulus. E.g. a tendon reflex is jerking of a muscle produced by striking certain tendons
Refractive Errors When the eye does not provide the correct amount of power for its size, more specifically the eyeball length, a refractive error results. When the eye provides too much power, the person is nearsighted. When the eye does not provide enough power, then the person is farsighted
Regurgitation To rush or surge back, especially to cast up partially digested food
Rehabilitation A programme of medicine and psychologicalal and clinical treatment designed to maximise residual physical, perceptual and cognitive abilities following injury, illness or disability.
Rejection of Transplant This occurs when the transplanted organ or tissue is attacked by the immune system of the person receiving the transplant. It is caused by the formation of antibodies in the recipient’s blood, which react with the transplanted organ, eventually leading to its destruction
Remission A lessening in the severity of symptoms or their disappearance during the course of the illness. Remission may be temporary or permanent.
Renal Relating to the kidney
Repetitive strain injury (RSI) A musculoskeletal disorder, generally affecting muscles or Tendons of the upper limbs and neck, resulting from repetitive and forceful motions or from activities carried out in awkward postures
Resection The surgical removal of part or all of an organ or part of the body
Respiration The act of breathing
Respirator An artificial device used to aid the act of respiration in those who are unable to do this adequately themselves. It is an old-fashioned term, the modern term is ventilator
Retardation Slowing down of mental and physical activity as often observed in depression
Retina The light- sensitive layer of cells (rods and cones) lining at the back of the eye. It converts the impressions produced by light into electrical impulses, which are then carried by the optic nerve to the visual cortex of the brain
Retinal detachment Separation of the retina from its attachments to the back of the eyeball resulting in loss of vision
Retinitis Pigmentosa A disease of the eye, resulting from degeneration of a part of the eye called the retina. It affects night vision and peripheral vision, and eventually can lead to blindness
Retinopathy Any disease or disorder of the retina. Most often found in diabetes and high blood pressure, sometimes leading to impairment of vision and blindness
Rheumatic Fever A childhood throat infection caused by septococcal bacteria resulting in a rash. A complication is damage to heart valves. Easily treated with Penicillin
Rheumatism A general term to describe disorders affecting the joints, muscles, tendons and ligaments
Rheumatoid Arthritis A chronic inflammation of the linings of joints and tendon heaths. In its usual form, it is a symmetrical, destructive and deforming arthritis
Rheumatology The branch of medicine concerned with the diagnosis and treatment of disorders of the joints, muscles, tendons and ligaments. A Rheumatologist is also concerned with connective tissue diseases
Rhinitis An inflammation of the mucous membrane that lines the nose
Rhonchi Wheezes audible with the stethoscope, indicating narrowing of small airways in the lungs
Ribonucleic Acid Ribonucleic acid is a polymeric constituent of all living cells and many viruses. The structure and base sequence of RNA are determinants of protein synthesis and the transmission of genetic information
Rickets A now rare disease of children caused by a lack of vitamin D, causing deformity of the lower limbs
Rodent Ulcer A slow-growing skin tumour involving cancerous changes in the skin cells known as basal skin cells
Rods Light sensitive nerve cells in the retina that tell light from dark and are responsible for night vision
Rombergs sign An inability to stand without swaying if the eyes are closed
Royal Free Disease Another name for Chronic Fatigue Syndrome. Also known as Post-viral Fatigue Syndrome or Myalgic Encephalomyelitis
Rubella German measles is a viral infection, which is characterised by a fine rash, sore throat and enlarged lymph glands
Rubella syndrome The abnormalities caused by infection with the rubella (German measles) virus before birth. The syndrome is characterized by multiple birth defects and learning difficulties
Rupture of tendon A tearing apart of a tendon

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S

Term Description
Sacroiliac joint The joint between the sacrum (the lower part of the backbone) and the ileal bones which form the back of the pelvis.
Sacrum The curved, triangular bone at the lower end of the backbone, located below the last (5th) lumbar vertebra. It consists of five fused vertebrae and articulates with the spine and the pelvis.
Salpingitis Inflammation of the Fallopian tubes.
Sarcoid Granulomata Nodules, which occur in organs, mainly the lungs as a result of sarcoidosis.
Sarcoidosis (Sarcoid) A disease of unknown cause, in which granular nodules affect many parts of the body, but principally the lungs.
Sarcoma A particular type of malignant tumour arising from bone, cartilage, muscle, fat or other related tissues.
Scapula Two flat bones that together form the shoulder blades.
Schizoid A pesonality disorder characterised by aloofness, coldness, discomfort in social interactions, intraversion, and excentricity
Schizophrenia A mental health disorder characterised by disturbances of thinking, perception, emotion and behaviour. It is one of the more severe mental illnesses often leading to serious recurrent and long-term disability
Schizotypal Exhibiting abnormalities in behavior and communication style similar to those of schizophrenia, but less severe
Schizo-affective disorder A mental disorder in which symptoms of schizophrenia occur in combination with symptoms of a mood disorder such as depression or mania.
Sciatica Pain down the back of the leg, usually caused by pressure on the sciatic nerves by a prolapsed inter-vertebral disc in the vertebral column.
Sclera The white, protective, outer layer of the eyeball.
Scleritis Inflammation of the sclera, the white part of the eyeball.
Scleroderma A connective tissue disorder, which may affect many organs characterised by thickening and hardening of the skin with consequent impairment of dexterity.
Sclerosis A hardening or thickening of tissues often used to describe blood vessels
Scoliosis A sideways curvature of the backbone to either the left or right.
Scrotum The pouch containing the testes
Seasonal Affective Disorder (SAD) A form of depressive illness in which there is a regular relationship between the onset of depressive episodes and a particular time or season of the year.
Sebaceous Numerous glands that usually open into the hair follicles and secrete an oily thick substance
Seborrhea A condition in which overactivity of the Sebaceous glands causes the skin to become oily
Secondary Generalised Seizure A seizure that begins in one part of the brain then spreads across the brain causing the person having the seizure to lose consciousness.
Secretion The production of substances by the glands of the body (e.g. saliva by the salivary glands).
Secretory Otitis Media Inflammation of middle ear mucosa, often accompanied by accumulation of fluid, secondary to eustachian tube obstruction
Sedative A depressant, which acts on the central nervous system to relieve anxiety and induce calmness/sleep (e.g. barbiturates, benzodiazepines).
Semantic Memory This is the brain’s knowledge store of objects, word meanings and facts such as Paris is the capital of France.
Seminoma A malignant tumour of the testicle.
Senescence The condition of being old.
Senility A state of mental deterioration resulting from old age.
Sensorineural Deafness Hearing loss or impairment due to a lesion or defect of the cochlea or the acoustic nerve
Sensory Relating to the senses (touch, vision, hearing, taste, smell).
Sensory nerves Those nerves responsible for the appreciation of touch, pain, temperature and position.
Sepsis Infection.
Septicaemia Presence of large numbers of bacteria in the blood, giving rise to a very severe illness with a high fever. Also known as blood poisoning.
Septum A thin partition or membrane that divides two cavities or soft masses of tissue in an organism e.g. the nasal septum or the atrial septum of the heart
Serology The characteristics of a disease or an organism shown by study of blood serums
Shingles An acute infection caused by a herpes virus. It usually strikes only one side of the body and is often accompanied by severe neuralgia. Also called herpes zoster, zona, zoster
Shock A condition, where the blood pressure falls so low that the blood supply to vital organs is threatened. Shock can be caused by severe injury with loss of blood, heart attack, severe allergic reaction and some infections.
Sickle-cell (drepanocytosis) A hereditary blood disease mainly affecting people of African ancestry.
Sickle-cell anaemia An autosomal dominant type of hemolytic anemia caused by hemoglobin S with abnormal erythrocytes (sickle cells) in the blood
Sigmoid colon The s- shaped part of the large bowel just above the rectum.
Silicosis A lung disease caused by the inhalation of silica particles, which may lead to progressive breathlessness and which occurs in miners, stone masons and quarry workers.
Simian Relating to or resembling an ape
Simple Partial A seizure that affects a small part of the brain (Frontal, Parietal, Temporal or Occipital lobes) and there is no loss of consciousness.
Sinoatrial See sinus node.
Sinus Node A group of specialised cells in the right atrium responsible for the electrical impulse in the heart. It functions as the heart's pacemaker, setting the pace for the heartbeat.
Sjogrens syndrome A syndrome resulting in a combination of dry eyes, dry mouth, enlarged parotid (salivary) glands, and polyarthritis. It is seen in at least 30% of people with rheumatoid arthritis.
Sleep apnoea A sleep disorder in which breathing is interrupted during sleep.
Snellen's chart A chart consisting of letters of varying sizes used for testing visual acuity
Social phobia A disorder that results in extreme anxiety in social situations.
Soft tissue rheumatism A variety of conditions affecting the tissues such as the muscles, tendons and ligaments, which surround joints, but not involving the joints themselves.
Somatic Relating to the body as opposed to the mind.
Spasmodic torticollis Involuntary contraction of one or more of the neck muscles resulting in the turning of the head to one side.
Spastic paralysis A paralysis in which the affected muscles are contracted with rigidity and stiffness of the limb.
Spatial neglect A term used to describe cognitive problems where a person is unable to recognise that one side of the body or visual field exists.
Special Needs Medical, emotional, mental or behavioural needs that will require on-going assistance and support. Educationalists use the term “Special Needs” as an alternative to learning disability.
Specific back pain This term applies to back pain where there is evidence of a definite and identifiable pathological cause for the person’s symptoms.
Specific phobia A type of phobia characterized by extreme fear of an object or situation that is not harmful under general conditions.
Sphincter A ring of muscle at the outlet of an organ e.g. bowel or bladder whose contraction prevents incontinence
Spina bifida A congenital abnormality of the spinal cord and vertebral column (back bone) in which there is a protrusion of the spinal cord, nerve roots, and meninges through a defect in the vertebral column leading to major physical effects.
Spina bifida occulta A very mild form of spinal bifida, which does not lead to any disability. It may only be shown up on routine X-Ray.
Spinal canal The boney channel formed by the vertebrae bones. The spinal cord and nerve roots lie within the canal and are protected by the bones.
Spinal claudication Leg and buttock pain when standing for long periods of time or when walking with the back in an extended position.
Spinal Cord Compression Spinal cord compression (pressing together) is a condition that causes pressure on the spinal cord, leading to narrowing or distortion of the nerve tissue
Spinal cord A column of nerve tissue that runs from the base of the skull down the back. It is enclosed within the vertebrae (back bones). The spinal cord and the brain make up the central nervous system, and spinal cord nerves carry most messages between the brain and the rest of the body.
Spinal stenosis A condition where the spinal canal narrows and pinches the spinal cord and nerves, usually due to disc herniation. This may affect the cervical spine, the lumbar spine or both, and results in low back pain as well as pain or abnormal sensations in the legs.
Spirometer An instrument used for measuring lung function
Spirometry The most common of the Pulmonary Function Tests (PFT), is the measurement of lung function, specifically the measurement of the amount (volume) and speed (flow) of air that can be inhaled and exhaled.
Spirometry Test A Spirometry test measures the volume of air blown out against time and gives specific information about lung function. Click here for more information about Spirometry Test
Spleen An organ found in the upper left part of the abdomen involved with the manufacture and destruction of blood cells.
Splenectomy Surgical removal of the spleen.
Splenomegaly Enlarged spleen.
Spondylitis Inflammation of the spinal joints as a result of degenerative changes.
Spondylolisthesis A sliding forward of one or more vertebra on another, usually in the lower part of the backbone and possibly causing back pain. An operation may be needed to correct it.
Spondylosis A condition resulting from degeneration of the discs between vertebrae with the formation of bony outgrowths and arthritis of joints between vertebrae. It is a degenerative condition, normally occurring with ageing. When occurring in the neck it is referred to as cervical spondylosis whilst when occurring in the lower spine is called lumbar spondylosis.
Spontaneous remission A lessening in the severity of symptoms or their disappearance during the course of the illness, without assistance from a therapist, counsellor, or medical practitioner. Remission may be temporary or permanent
Sporadic goitre A type of goitre where only some individuals are affected, this may be due to an inherited familial tendency, poor individual diet, age (over 40 years) and gender, certain foods or medication.
Sprain A sprain is an injury to a ligament.
Sputum Mucus and other matter that is brought up from the lungs by coughing.
Squamous cell carcinoma A malignant tumour arising from squamous epithelium
SSRI Antidepressants Second generation antidepressive agents, which inhibit serotonin reuptake
Stapedectomy Surgical removal of all or part of the stapes of the middle ear, followed by replacement with a prosthesis
Stapes The final bone in the series of three small bones, or ossicles, of the middle ear. Sometimes called the stirrup.
Statins Cholesterol-lowering drugs.
Status Asthmaticus A very severe and prolonged attack of asthma, which does not respond to standard medical treatment.
Status epilepticus A series of epileptic seizures during which the person does not regain consciousness between each fit.
Steatorrhoea The presence of excess fat in the stools, which causes them to be bulky and offensive. Found when absorption of fats from the bowel is impaired as, for example, in cystic fibrosis.
Stenosis A narrowing. Commonly used in relation to the valves of the heart whose narrowing may lead to heart failure. (E.g. aortic stenosis). Also applied to the narrowing of an artery (E.g. carotid stenosis).
Stent A narrowing. Commonly used in relation to the valves of the heart whose narrowing may lead to heart failure. (E.g. aortic stenosis). Also applied to the narrowing of an artery (E.g. carotid stenosis)
Sternum A longitudinal unpaired plate of bone forming the middle of the anterior wall of the thorax, articulating above with the clavicles and along its sides with the cartilages of the first seven ribs (known as the breast bone)
Sternocleidomastoid Muscles that run at the front of the neck from behind the ear to the upper end of the breast bone and inner part of the collar bone
Steroid A particular type of hormone produced by the adrenal glands or a synthetic version used to treat certain conditions.
Stethoscope Any of various instruments used for listening to sounds produced within the body (usually the chest)
Still's disease A form of rheumatoid arthritis affecting children. (See Rheumatoid Arthritis).
Stimuli That which can elicit or evoke an action or response in a cell, an excitable tissue, or an organism
Stokes-Adams Attack Syncope (a simple faint) caused by a drop in blood pressure secondary to a fall in cardiac output due to an arrhythmia
Stoma An artificial opening of a tube. E.g. colostomy
Stomach An organ situated in the upper part of the abdomen joining the oesophagus (gullet) to the small intestine.
Stomatitis Inflammation of the mouth.
Strabismus A squint.
Stricture An abnormal narrowing of a bodily passage due to trauma, inflammation, cancer or the formation of scar tissue
Stridor Harsh, noisy breathing caused by partial obstruction of the upper part of the airway.
Stroke Weakness of one side of the body sometimes associated with cognitive function usually as a result of a brain haemorrhage or blockage of a brain artery.
Stromal A type of tissue that is associated with the support of cells within an organ of the gastrointestine
Stupor A state of semi-consciousness.
Sub-arachnoid Haemorrhage A bleed into the space surrounding the brain causing a sudden severe headache and which may lead to residual effects similar to those of a stroke.
Sub-arachnoid Space The sub-arachnoid space contains a clear fluid, the cerebro-spinal fluid (or CSF) and small blood vessels that supply the outer surface of the brain
Sub-clinical Without clinical manifestations
Sub Cortical Refers to the structure under the cortex, the outer layer of the brain.
Sub Cortical Dementia Any of a group of dementias thought to be caused by lesions affecting subcortical brain structures. Included are vascular dementia and dementias that accompany Huntington's chorea, Wilson's disease, paralysis agitans, and thalamic atrophies
Subdural Haematoma A blood clot beneath one of the membranes surrounding the brain usually as a result of injury. It is a medical emergency, and removal of the clot may lead to complete recovery. Sometimes it occurs as a result of minor injury in the elderly which may be difficult to diagnose, and may lead to progressive mental impairment.
Subluxation An incomplete or partial dislocation.
Sulphone A type of drug e.g. Metformin to treat diabetes mellitus Type 2
Supination Rotating a hand or foot outward on its long axis. The movement is done with the muscles in the forearm or lower leg.
Supine Lying on the back with the face upwards.
Supraventricular Situated or occurring above the ventricles
Surgery The branch of medicine, which treats disease or injury by operative measures.
Sympathetic nerves One of two types of nerves responsible for controlling functions which take place at the unconscious level.
Sympathetic nervous system The thoraco-lumbar part of the autonomic nervous system, the preganglionic fibres of which are distributed to the heart, smooth muscle, and glands of the entire body
Symptomatic Showing symptoms, e.g. of a particular disease.
Syncope A simple faint or temporary and very brief loss of consciousness.
Synovial fluid A fluid within the joint, which assists in lubrication and nutrition of the joint.
Synovium A thin membrane (normally one or two cell layers thick) lining the inside of the joint capsule. It produces synovial fluid
Synovitis The inflammation of the membrane, (synovium) which lines a joint.
Synthesis The combining of separate elements or substances to form a coherent whole e.g. to make a protein - "protein synthesis."
Syringomyelia A progressive condition of the spinal cord leading to weakness of upper and lower limbs and particularly with loss of pain and temperature sensation in the arms.
Systemic Relating to the body as a whole.
Systemic lupus erythematosus (SLE) Inflammatory connective tissue disorder with variable features, including fever, fatigue, arthritis and joint pain, and red skin lesions on the face, neck, and/or upper limbs.
Systolic blood pressure The first of two numbers used to measure blood pressure. The peak of blood pressure caused by contraction pressure of the heart.

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T

Term Description
T Cell A particular type of white blood cell
Tachycardia A rapid heart beat
Tachypnoea A rapid respiratory rate
Talipes A congenital deformity of the foot, commonly known as clubfoot
Tardive dyskinesia A side effect of anti psychotic medication involving rhythmic, involuntary movements of the tongue, face, jaw, trunk or limbs
Tarsalgia Pain in the foot
Telangiectasia Permanent dilation of pre-existing small blood vessels creating focal red lesions, which may present as a coarse or fine red line or as a punctum with radiating limbs
Temporal Lobe Epilepsy A seizure that affects the temporal lobe. They are characterized by episodes of loss of awareness or contact with surroundings. During a temporal lobe seizure, the person may display automatisms. Temporal lobe seizures may be followed by confusion for a few minutes
Tendon A tough cord of fibrous tissue attaching a muscle to a bone
Tendonitis An inflammation in a tendon or the tendon covering
Tennis elbow A condition characterised by inflammation of the tendon at the outer border of the elbow. Also known as Lateral Epicondylitis. It is a result of a specific strain or overuse
Tenosynovitis Inflammation of the sheath surrounding a tendon
Teratoma A tumor consisting of different types of tissue, as of skin, hair, and muscle, caused by the development of independent germ cells; usually found in the ovary or testis
Terminal Causing, ending in, or approaching death; fatal
Testosterone Male steroid hormone, produced primarily in the testes and responsible for the development and mantenance of male sex characteristics
Tetraplegia (quadriplegia) Paralysis of all four limbs The person is paralysed from the neck downwards
Thalassaemia (Cooley’s anaemia) A hereditary blood disease, widespread in the Mediterranean countries, Asia, and Africa
Theca A sheath surrounding the spinal cord
Therapeutics The science of the healing of diseases with drugs and other measures
Thiamine The chemical name for Vitamin B1 that is found in whole wheat, bread. Vitamin B helps with growth, digestion and maintaining healthy nerves
Thoracic outlet syndrome Tingling sensations in the fingers; caused by compression on a nerve supplying the arm
Thorax The chest
Thrombo-embolic Relating to or as a result of a thrombosis or embolism
Thrombocytopenia A reduction in the number of platelets in the blood leading to abnormal bleeding
Thrombosis The sudden formation of a clot within a blood vessel leading to a stoppage of blood flow
Thrombotic Stroke A type of ischaemic stroke where the blood clot forms in the artery itself. This commonly occurs over a patch of fatty tissue called atheroma (this is often called furring up or hardening of the arteries). Atheroma is common in older people. If a patch of atheroma becomes large enough it can trigger the blood passing over it to clot. The blood clot so formed stays attached to the wall of the artery until it grows big enough to block the flow of blood. This type of fixed blood clot is called a thrombus
Thrombus A fibrinous clot formed in a blood vessel or in a chamber of the heart
Thrush Candidiasis, commonly called yeast infection or thrush, usually of the vagina or mouth
Thymectomy Surgical removal of the thymus gland
Thymoma This is the common tumour of the Thymus
Thymus An organ near the base of the neck that produces cells that fight infection
Thyroid Disease When the thyroid produces too much hormone, this condition is called hyperthyroidism. When the thyroid doesn’t produce enough hormone, this condition is called hypothyroidism
Thyroid gland A gland situated in the front of the neck producing hormones, which regulate the body's rate of metabolism
Thyroidectomy The surgical removal of all (total) or part of (partial) the thyroid gland
Thyroiditis An inflammation of the thyroid gland
Thyrotoxicosis (Hyperthyroidism) Overactivity of the thyroid gland leading to weight loss, rapid pulse, excessive sweating, irritability and intolerance of the heat
Thyroxine The hormone produced by the thyroid gland, which controls the rate of metabolism in the body
Tibia The shinbone. The larger of the two bones in the lower leg
Tic A spasmodic, involuntary twitching of certain muscles, usually of the face
Tinnitus A ringing, buzzing or roaring sound in the ears
Todd's paralysis A neurological condition characterized by a brief period of temporary paralysis following a seizure
Tone The degree of tension within a muscle
Tonic-Clonic A type of generalised seizure resulting in loss of consciousness, and usually associated with incontinence, tongue biting, muscle contractions and a period of confusion following the seizure
Tonic Seizure A type of generalized seizure that involves stiffening or rigidity of the entire body. May or may not be loss of consciousness
Tonometry The measurement of tension or pressure, particularly intraocular pressure
Torticollis (Wry-neck) Contraction of one or more of the neck muscles resulting in the abnormal turning of the head to one side with rotation on an angle. Also known as “Wry Neck”
Tourette Syndrome Gilles de la Tourette Syndrome
Toxaemia Another term for blood poisoning, or the presence in the bloodstream of quantities of bacteria or bacterial toxins sufficient to cause serious illness
Toxic Able to cause harmful health effects
Toxoplasmosis Toxoplasmosis is a disease caused by a parasite, and is present in raw and undercooked meat, and cat faeces. The infection may be asymptomatic or may cause heart or nervous system problems. Congenital toxoplasmosis occurs in babies born to infected mothers and presents with severe neurological damage
Trabeculectomy An operation for glaucoma in which a hole is made in the coating of the eye to increase drainage
Trachea The windpipe
Tracheostomy A surgical procedure in which an opening into the trachea is made through the neck
Trans-urethral resection Surgical removal of part of an organ or structure through the urethra
Transient Remaining in place for only a brief time
Transient Ischaemic Attack (TIA) A short lived reduction of blood supply to the brain leading to temporary symptoms such as dizziness, weakness, vision loss, slurred speech, confusion which lasts for less than 24 hours
Transitional Cell Carcinoma A malignant neoplasm derived from transitional epithelium.
Transsexual A person whose gender identity is opposite to his or her physical state
Transvestite A person who dresses as a member of the opposite sex
Trauma A wound or injury
Treadmill Test A test where the patient walks at increasing speed and incline. The patient's heart rate and ECG is monitored throughout the test. Sometimes called the Bruce Protocol Test. Click here for more information on the Bruce Protocol Test
Tremor Involuntary muscular activity leading to rhythmic movements of the particular part of the body affected. There is alternating contraction and relaxation of muscles of a particular part of the body. Commonly occurs in Parkinson's disease
Triceps A muscle situated at the back of the arm responsible for straightening the elbow
Trichotillomania A compulsion to pull out one's own hair
Tricuspid Valve A valve located between the heart's upper and lower chambers on the right side. The three (“tri”) cusps of this valve allow one-way blood flow from the upper-right atrium into the lower-right ventricle
Tricyclics A class of antidepressants drugs. Although these drugs are generally effective, there are often serious side-effects
Trigeminal neuralgia Sharp, shooting intense pain in the face confined to the area of skin supplied by a branch of the trigeminal nerve
Trigger Factors Factors, which bring on the symptoms of an impairment. E.g. house dust mites bringing on an asthma attack in susceptible individuals
Trigger Finger/Thumb A type of stenosing tenosynovitis in which the sheath around a tendon in a thumb or finger becomes swollen and restricts the tendon's movement. Affected joints may become painful to straighten once bent, and may make a soft crackling sound when moved
TSH (Thyroid Stimulating Hormone or Thryotopin) A hormone produced by the pituitary gland to regulate the action of other hormone-secreting glands in the body. One of these hormones is thyroid-stimulating hormone (TSH or thryotropin), which stimulates the thyroid to produce thyroid hormone
Tuberculin Test Any of various skin tests used to determine infection or immunity with Mycobacterium tuberculosis, in which tuberculin or its purified protein is introduced into the skin by injection or tines
Tuberculosis A slowly progressive infectious disease, which may affect many parts of the body, but which most notably causes a long standing infection of the lungs. Because of its slow onset, it is sometimes difficult to diagnose, but it can usually be cured with appropriate drugs
Tuberous Sclerosis A genetic disorder characterised by multiple tumours in the skin, brain and other vital organs. The condition develops before birth and may present with epilepsy, learning difficulty and skin lesions
Tumour A mass of abnormally growing cells that serve no useful bodily function. Tumours can be either benign (non-cancerous) or malignant (cancerous)
Tunnel vision A condition in which a person lacks any peripheral vision. Tunnel vision can be caused by any number of conditions including glaucoma, retinitis pigmentosa, and stroke
Tympanic membrane The eardrum. It separates the outer ear from the middle ear
Tympanoplasty Surgical repair or reconstruction of the middle ear
Tyrosinosis A rare, possibly inherited disorder of tyrosine metabolism characterised by enhanced urinary excretion of certain metabolites upon ingestion of tyrosine

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U

Term Description
Ulcer An erosion or loss of continuity of a lining membrane, eyes, lining of the mouth, oesophagus, stomach or intestine
Ultrasound A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of blood vessels, tissues, and organs called a sonogram. Also called ultrasonography
Unilateral On one side only (of the body)
Uraemia A condition characterised by a high level of urea (a waste product) in the blood, being one of the manifestations of renal failure
Unremitting Constant, incessant, never-ending, perpetual, unceasing
Urea The main end product of protein metabolism, which circulates in the blood and is eliminated from the body by the kidneys
Ureter A long muscular tube which connects each kidney to the bladder
Ureteroscope An endoscope used for examination of the ureter
Urethra The tube through which urine is discharged from the bladder (to the outside of the body)>
Urethrotome An instrument used for cutting a urethral stricture
Urostomy Surgical construction of an artificial excretory opening from the urinary tract
Urticaria Hives or nettle rash. Often caused by contact with e.g. plants or with an allergen to which a person is allergic. The rash usually resolves within 24 hours. See also chronic urticaria.
Uterus The womb
Uveitis Inflammation of the middle part of the eye (known as “uvea”). This generally refers to the iris of the eye

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V

Term Description
Vagotomy Surgical cutting of the vagus nerve, a procedure occasionally used in the treatment of peptic ulcer (it causes the stomach to produce less acid).
Vagus Nerve Stimuation (VNS) Vagus nerve stimulation (VNS) is designed to prevent seizures by sending regular, mild pulses of electrical energy to the brain via the vagus nerve. These pulses are supplied by a device something like a pacemaker placed under the skin on the chest wall and a wire runs from it to the vagus nerve in the neck.
Valgus A displacement outwards as in Genu valgum where the person has knock knees with deviation of the lower legs outwards, or Hallux valgus where the big toes are displaced outwards.
Valvular Heart Disease Damage to (e.g. caused by rheumatic heart disease) or congenital abnormalities of the heart.
Varix Dilatation of a vein
Varicose Abnormally swollen or dilated, as in varicose veins.
Varicose Ulcer A skin ulcer, usually near the ankle, due to varicose veins. Varicose ulcers are very slow to heal, needing a prolonged period of rest, with the legs raised up
Varus A displacement (for example, of a bone) inwards towards the midline, as in Genu varum where the patient has bowlegs with the lower legs deviated inwards.
Vascular Relating to the blood vessels.
Vascular Dementia A dementia caused by impaired blood supply to the brain It may follow a stroke or multi infarctions of the brain (Transient Ischaemic Attack - mini-strokes)
Vasculitis Inflammation of a blood vessel. A common pathological feature in a number of rheumatic and multi-system disorders
Vasodilators Vasodilators are medicines that act directly on muscles in blood vessel walls to make blood vessels widen (dilate)
Vasovagal attack A term used to describe a simple faint.
Vein A blood vessel carrying blood back from the tissues/lungs to the heart.
Vena cava Either of the two large vein, which carry deoxygenated blood from all parts of the body and which lead directly into the heart (the right atrium). The Superior Vena Cava returns the blood from the upper part of the body, and the Inferior Vena Cava returns the blood from the lower part of the body.
Venereal disease Disease contracted through sexual contact. Also known as STD or Sexually Transmitted Disease.
Veno occlusive disease Disease contracted through sexual contact. Also known as STD or Sexually Transmitted Disease
Venous Thrombosis The presence of a blood clot along the wall of a vein
Ventilator An artificial device used to aid the act of respiration in those who are unable to do this adequately themselves. They used to be called Respirators
Ventricle The name given to each of the two large chambers in the heart, the left and right ventricles. They collect blood from the atria and pump it out of the heart, the right ventricle to the lungs, and the left ventricle to the body. Also the name given to the fluid filled cavities within the brain, which are filled with cerebrospinal fluid, which bathes and protects the brain and cerebrospinal cord.
Vertebra One of the 33 small bones which form the spinal column or backbone.
Vertebral artery Either of the two large blood vessels at the side of the neck, supplying blood to the top of the spinal cord and the back part of the brain (posterior).
Vertigo The feeling that either oneself or one's surroundings is spinning round. There is associated nausea and vomiting. It is most frequently associated with disease of the inner ear such as Meniere's disease, Strokes and Multiple Sclerosis (MS).
Vestibular Labyrinth The portion of the inner ear that functions as part of the body's balance mechanism.
Virology The study of viruses and the diseases they cause
Victrectomy An operation designed to remove diseased vitreous and repair or protect the retina.
Videotelemetry A special type of EEG (brainwave) test. The brainwaves are recorded usually for several days along with a video of the patient.
Viral hepatitis Inflammation of the liver caused by a virus
Visual cortex The part of the cerebral cortex of the brain that is responsible for processing visual stimuli.
Visual Field The area a person can see around an object without head movement, when looking directly at it. It is measured in degrees; a normal visual field extends about 95 degrees to the sides, 60 degrees upwards 75 degrees downwards.
Visual Impairment Visual impairment occurs when there is an abnormality of structure or function of the eye.
Visuospatial Refers to our ability to process and interpret visual information about where objects are in space. This is an important aspect of cognitive functioning because it is responsible for a wide range of activities of daily living. For instance, it underlies our ability to move around in an environment and orient ourselves appropriately. Visuospatial perception is also involved in our ability to accurately reach for objects in our visual field and our ability to shift our gaze to different points in space.
Vitreous The thick gelatinous material that fills the back of the eye in front of the retina.
Vitreous humour Transparent jelly filling globe between crystalline lens and retina.

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W

Term Description
Weal (Hive) A transient swelling, confined to a small area of the skin, that is characteristic a urticaria.
Wernicke Korsakoff Syndrome A brain disorder due to thiamine deficiency in alcohol abuse, or those with damage to the forebrain, have such poor memory, that they are unable to repeat something after a few seconds and have to invent new information to fill in the gaps in their memory.
Wernicke's Encephalopathy An acute state of confusion associated with abnormal eye movements and co-ordination difficulties due to Thiamine deficiency, commonly seen in chronic alcoholism.
Whiplash injury Injury to the soft tissues and sometimes the nerves in the neck due to sudden forward and backward jerking movement of the head, commonly seen in road traffic accidents.
von Willebrand's disease An inherited form of bleeding/clotting disorder.
Wilms' tumour A malignant tumour of the kidney occurring in young children.
Wilson's Disease Wilson's disease is an inherited disorder causing the body to absorb and retain copper predominantly in the liver, brain, kidneys and eyes
Wolff Parkinson White Syndrome A congenital abnormality of the mechanism regulating the heartbeat, resulting in palpitations (bursts of very rapid heart rate).
Work-related Upper Limb Disorder (WRULD) Conditions that may be associated with repetitive movement disorders of the upper limbs
Writers cramp A focal dystonia where the effect is limited to the hand

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X

Term Description
X Chromosome The female sex chromosome, each female cell containing 2 of them
X-ray A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer

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Y

Term Description
Y Chromosome The male sex chromosome, each male cell containing one Y and one X chromosome
Abdominal cavity- the part of the body between the bottom of the ribs and the top of the thighs, containing most of the digestive and urinary systems along with some reproductive organs

ABO blood groups- The system by which human blood is classified, based on proteins occurring on red blood cells; the four classification groups are A, AB, B, and O

Abortion- termination of a pregnancy; can occur because of natural causes (called a miscarriage) or be a medical intervention

Abscess- an accumulation of pus in a body tissue, usually caused by a bacterial infection

ACE inhibitor- a drug typically used to treat high blood pressure (Angiotensin-Converting Enzyme inhibitor)

Achilles tendon- the tendon at the back of the lower leg that connects the calf muscle to the heel bone

Acid-base balance- the mechanisms that the body uses to keep its fluids close to neutral (neither basic nor acidic) so that the body can function properly

Acidosis- a condition marked by abnormally high acid levels in the blood, associated with some forms of diabetes, lung disease, and severe kidney disease

Acid reflux- a disorder in which acid in the stomach comes up into the esophagus, because the valve separating the stomach and esophagus does not function properly Acne- a skin condition characterized by inflamed, pus-filled areas that occur on the skin's surface, most commonly occurring during adolescence

Acquired- a word describing any condition that is not present at birth, but develops some time during life

Acute- describes a condition or illness that begins suddenly and is usually short-lasting

Acute respiratory disease- an urgent condition in which oxygen levels in the blood are lower than normal and breathing is difficult

Addiction- dependence on a substance (such as alcohol or other drugs) or an activity, to the point that stopping is very difficult and causes severe physical and mental reactions

Adenitis- infection and inflammation of a gland, especially a lymph node Adipose tissue- another term for fatty tissue; it stores energy, insulates, and cushions the body

Adjuvant therapy- the use of drugs or radiation therapy in the treatment of cancer along with surgery

Adrenal failure- a condition in which the adrenal glands do not produce enough of the hormones that control important functions such as blood pressure

Adrenal glands- two small glands located on top of the kidneys that secrete several important hormones into the blood

Adverse reaction- an unintended and unwanted side effect of some sort of treatment, usually drug therapy

Aerobic exercise- physical activity during which the heart and lungs must work harder to meet the body's increased oxygen demand

Affective disorder- a mental disorder involving abnormal moods and emotions; affective disorders include manic-depressive disorder

Afterbirth- the placenta and membranes that are eliminated from the woman's uterus following the birth of a child

Afterpains- normal contractions of the uterus after childbirth that usually occur for the first few days after delivery

Air embolism- the blockage of an artery by air bubbles, which may have entered during surgery or after an injury

Airway obstruction- blockage of the passage of air through the windpipe to the lungs

Airways- the passageways that air moves through while traveling in and out of the lungs during breathing

Albinism- a condition in which people are born with insufficient amounts of the pigment melanin, which is responsible for hair, skin, and eye color

Alcoholic cardiomyopathy- heart damage and failure caused by intake of too much alcohol

Alimentary canal- another term for the digestive tract

Alkalosis- dangerously decreased acidity of the blood, which can be caused by high altitudes, hyperventilation, and excessive vomiting

Alkylating agents- substances used in cancer treatment that interfere with the division of cells

Allergen- a substance that causes an allergic reaction

Allergic rhinitis- irritation of the nasal passages and the whites of the eyes, causing sneezing, runny nose, and sore eyes

Allergy- a negative reaction to a substance that in most people causes no reaction

Alopecia- baldness or loss of hair, mainly on the head, either in defined patches or completely; the cause is unknown

ALS- see Amyotrophic lateral sclerosis

Altitude sickness- headaches, dizziness, and nausea usually experienced at heights above 8,000 ft because of reduced oxygen in the air

Alzheimer disease- a condition that occurs late in life and worsens with time in which brain cells degenerate; it is accompanied by memory loss, physical decline, and confusion

Amenorrhea- absence of menstrual periods, occurring either after or before menstruation has begun

Amniocentesis- a procedure in which a small amount of amniotic fluid is removed from the mother’s womb in order to detect abnormalities of the fetus

Amniotic fluid- clear fluid that surrounds a fetus during pregnancy and cushions and protects it

Amyotrophic lateral sclerosis- the most common of a group of disorders known as motor neuron diseases, in which the nerves in the brain that control the movement of muscles degenerate and muscle function is gradually lost; commonly called Lou Gehrig's disease

Anabolic steroid- a drug similar to the male hormone testosterone that builds muscles and strengthens bones, but has adverse side effects

Anal fissure- a long, open sore on the skin of the anus

Anal fistula- an abnormal tubelike passage connecting the anus to the surface of the surrounding skin

Analgesic- a drug that relieves pain, such as aspirin or acetaminophen

Anal sphincter- a ring of muscle fibers at the opening of the rectum, controlling the opening and closing of the anus

Anaphylactic shock- a life-threatening allergic reaction resulting in difficulty breathing and low blood pressure

Anatomy- the structure of bodies; commonly refers to the study of body structure

Androgen- a hormone (such as testosterone) that causes development of male characteristics and sex organs

Anemia- a condition in which the blood does not contain enough hemoglobin, the compound that carries oxygen from the lungs to other parts of the body

Anencephaly- a fatal birth defect in which the brain and spinal cord have failed to develop, resulting in the absence of a portion of the skull and brain

Anesthesia- a loss of sensation in a certain part of the body or throughout the body

Anesthetic- a substance that temporarily causes a person to be unable to feel pain, either in a certain area or over the entire body

Aneurysm- an abnormal swelling of the wall of an artery, caused by a weakening in the vessel wall

Angina pectoris- pain experienced in the chest, arms, or jaw because of a lack of oxygen to the heart muscle

Angioma- a tumor made of blood vessels or lymph vessels that is not cancerous

Angioplasty- the use of surgery to make a damaged blood vessel function properly again; may involve widening or reconstructing the blood vessel

Anorexia nervosa- a dangerous eating disorder mainly affecting young girls in which the sufferer has an intense fear of looking fat, avoids food, and loses weight excessively

Antacid- a drug that neutralizes stomach acids; used to treat indigestion, heartburn, and acid reflux

Antibiotic resistance- the development by bacteria of the ability to live in the presence of a certain antibiotic, making treatment difficult

Antibiotics- bacteria-killing substances that are used to fight infection

Antibody- a protein made by white blood cells that reacts with a specific foreign protein as part of the immune response

Anticoagulants- drugs used to stop abnormal blood clotting, such as to prevent stroke

Antiemetics- drugs used to treat nausea and vomiting

Antihistamine- a drug that relieves an allergic reaction by stopping the effects of histamine, the substance responsible for the negative symptoms associated with the reaction

Antihypertensives- drugs used to relieve the symptoms and prevent the damage that can occur from high blood pressure

Antioxidants- substances that protect against cell damage by guarding the cell from oxygen free radicals

Antipsychotics- drugs used to treat severe mental disorders

Antiseptics- chemicals applied to the skin that prevent infection by killing bacteria and other harmful organisms

Anus- the opening through which feces are passed from the body

Aorta- the main artery in the body, carrying oxygenated blood from the heart to other arteries in the body

Aortic stenosis- narrowing of the opening of the aortic valve in the heart, which increases resistance to blood flow from the left ventricle to the aorta; commonly a birth defect or caused by scarring and calcium accumulation in the valve from rheumatic fever

Apgar score- a system for evaluating the health of a newborn baby; rated on a scale of 0-10

Aplasia- the complete or partial failure of any organ or tissue to grow

Aplastic anemia- a severely reduced number of red blood cells, white blood cells, and platelets

Apnea- a possibly life-threatening condition in which breathing stops, for either a short or long period of time

Appendectomy- surgical removal of the appendix to treat appendicitis

Appendicitis- inflammation of the appendix

Appendix- a short, tubelike structure that branches off the large intestine; does not have any known function

ARC- see AIDS-related complex

Arteriosclerosis- a disorder causing thickening and hardening of artery walls

Arteritis- inflammation of the walls of an artery that causes the passageway to become narrower; can lead to tissue damage because oxygen is not properly supplied

Artery- a large blood vessel that carries blood from the heart to tissues and organs in the body

Arthritis- a disease of the joints characterized by inflammation, pain, stiffness, and redness

Arthroscopy- a procedure used to examine the inside of a joint using a viewing tube (an endoscope)

Artificial insemination- injection of semen into the cervix

Artificial respiration/ventilation- the forcing of air (either by mouth-to-mouth or mouth-to-nose means) into the lungs of a person who has stopped breathing

Ascites- excess fluid in the abdominal cavity, which leads to swelling

Ascorbic acid- the chemical term for vitamin C

Aspermia- the failure either to produce or to ejaculate sperm

Asphyxia- the medical term for suffocation; can be caused by choking on an object, by lack of oxygen in the air, or by chemicals such as carbon monoxide, which reduce the amount of oxygen in the blood

Asthma- a disorder characterized by inflamed airways and difficulty breathing

Astigmatism- a disorder in which the front surface of the eye (the cornea) is not correctly spherical, resulting in blurry vision

Atherectomy- a procedure performed to remove plaque that is blocking an artery

Atheroma- fatty deposits on the inner walls of blood vessels, which can cause narrowing and decrease blood flow

Atherosclerosis- narrowing of the lining of the arteries due to the accumulation of fat and other materials; leads to coronary heart disease, stroke, and other disorders

Athlete's foot- an infection between the toes caused by a fungus, which leads to sore, cracked, and peeling skin

Atresia- a birth defect in which a normal body opening or canal is absent; usually requires surgical repair soon after birth

Atria- the two upper chambers of the heart; the singular form is atrium

Atrial fibrillation- an irregular heartbeat in which the upper chambers of the heart (the atria) beat inconsistently and rapidly

Atrial flutter- an irregular heartbeat in which the upper chambers of the heart (the atria) beat rapidly but consistently

Atrial septal defect- a hole located in the wall between the two upper chambers of the heart

Atrophy- the shrinkage or near disappearance of a tissue or organ

Attention-deficit disorder- a disorder mainly present in children and adolescents, characterized by learning and behavior problems, inability to pay attention, and sometimes hyperactivity

Audiogram- a graph showing a person's hearing ability, determined from a set of tests examining hearing acuity of different sound frequencies

Aura- a "warning" signal that comes before a migraine headache or an epileptic seizure, which might include emotions or sensations of movement or discomfort

Auscultation- the act of listening to sounds within the body, such as the heartbeat, with a stethoscope

Autism- a mental disorder characterized by an inability to relate to other people and extreme withdrawal

Autoimmune disease- a disorder in which the body’s immune system attacks itself Autonomic nervous system- the part of the nervous system that controls automatic body functions, such as heart rate, sweating, pupil dilation, and digestion; divided into the sympathetic nervous system and the parasympathetic nervous system

Autopsy- the examination of a body following death, possibly to determine the cause of death or for research

Autosomal dominant- a term describing a gene on any chromosome other than the sex chromosomes that produces its effect whenever it is present; can also describe the effect of the gene itself

Autosomal recessive- a term used to describe a gene on any chromosome other than the sex chromosomes that produces its effect only when two copies of it are present; can also describe the effect of the gene itself

Axilla- medical term for the armpit

B

Bacillus- any bacteria that is rod-shaped; responsible for diphtheria, dysentery, tetanus, and tuberculosis, as well as other diseases

Bacteremia- a condition in which bacteria are present in the bloodstream; may occur after minor surgery or infection and may be dangerous for people with a weakened immune system or abnormal heart valves

Bacteriostatic- term used to describe a substance that stops the growth of bacteria (such as an antibiotic)

Bacterium- a tiny, single-celled microorganism, commonly known as a germ; some bacteria, called pathogens, cause disease

Bacteriuria- bacteria in the urine; large amounts can indicate bladder, urethra, or kidney infection

Ball-and-socket joint- a joint consisting of a ball-shaped bone that fits into a cup-shaped bone, making the joint free to rotate; examples include the hip and shoulder

Balloon angioplasty- a technique that uses a balloon catheter to open arteries clogged with fatty deposits

Balloon catheter- a hollow tube with a small, inflatable balloon at the tip; used to open a narrowed artery or organ that has become blocked

Barbiturates- a group of sedatives that reduce activity in the brain; are habit-forming and are possibly fatal when taken with alcohol

Barium enema- a technique in which barium is placed into the large intestine and rectum and then X-rays are taken to check for possible disorders of these organs

Barrier method of contraception- a birth-control technique using a condom, diaphragm, or another similar device to block the path of sperm to an egg

Bartholin's glands- two pea-sized glands that, when sexually aroused, release a fluid that lubricates the vagina

Basal cell carcinoma- a type of skin cancer that is caused by exposure to large amounts of sunlight; commonly found on the neck, face, and arms

Basal metabolic rate- the lowest rate at which a person can possibly use energy and remain alive; at this rate, only absolutely necessary functions such as breathing are maintained

B cell- a white blood cell that makes antibodies to fight infections caused by foreign proteins

BCG vaccine- a vaccine used to protect against tuberculosis Becker’s muscular dystrophy- a hereditary disease in which the muscles weaken and waste away; similar to Duchenne muscular dystrophy but starts later in life and advances more slowly

Bell's palsy- another name for facial palsy, the usually one-sided, temporary numbing of the facial muscles, caused by an inflamed nerve

Bends- see Decompression sickness

Benign tumor- a tumor that is not cancerous, which means it does not spread through the body, but may grow and become dangerous

Beta blocker- a type of drug used to treat high blood pressure and heart disorders by reducing the strength and rate of the pumping by the heart

Beta carotene- a pigment found in orange vegetables and fruits, which the body converts to vitamin A; possibly protects against cancer

Bifocal- a lens that corrects both near and distant vision by having two parts with different focusing strengths

Bilateral- a term describing a condition that affects both sides of the body or two paired organs, such as bilateral deafness (deafness in both ears)

Bile- a yellow-green liquid produced in the liver whose function is to remove waste from the liver and break down fats as food is digested

Bile duct- a tube that carries bile from the liver to the gallbladder and then to the small intestine

Biliary atresia- a birth defect in which the bile ducts are not completely developed; often a liver transplant is necessary

Biliary colic- a severe pain in the upper right section of the abdomen, usually caused by a gallstone passing out of the bladder or through the bile ducts

Biliary tract- the system of organs and ducts through which bile is made and transported from the liver to the small intestine

Bilirubin- the orange-yellow pigment in bile, causing jaundice if it builds up in the blood and skin; the levels of bilirubin in the blood are used to diagnose liver disease

Binging and purging- behavior characteristic of the disorder bulimia in which a person overeats then rids themselves of the food before it can be absorbed by the body, either by forced vomiting or through the use of laxatives

Biochemistry- the science that studies the chemistry of living organisms, including humans

Bioequivalent- a drug that has the same effect on the body as another drug

Biofeedback- a technique used to gain control over a function that is normally automatic (such as blood pressure or pulse rate); the function is monitored and relaxation techniques are used to change it to a desired level Bipolar disorder- an illness in which the patient goes back and forth between opposite extremes; the most notable bipolar disorder is manic-depressive disorder, which is characterized by extreme highs and lows in mood Birth canal- the passage that includes the uterus and vagina through which the baby passes at birth

Birth control- the regulation of the number of children born, referring either to the prevention of pregnancy (by birth control pill, sterilization, etc) or the prevention of birth (by abortion, etc)

Birth defect- an abnormality that is present when a baby is born Birthmark- any area of discolored skin that is present when a baby is born Bisexuality- sexual interest in members of both sexes Bladder- an organ located in the pelvis whose function is to collect and store urine until it is expelled

Blepharitis- inflammation of the eyelids

Blind spot- a spot in the field of vision that is not sensitive to light; it is a product of the entrance of the optic nerve into the eyeball, where no light receptors are present on the retina

Blood-brain barrier- a layer of tightly bound cells that prevents certain substances carried in the bloodstream from entering the brain

Blood clot- a semisolid mass of blood that forms to help seal and prevent bleeding from a damaged vessel

Blood poisoning- see Septicemia

Blood pressure- the tension in the main arteries that is created by the beating of the heart and the resistance to flow and elasticity of the blood vessels

Blood transfusion- the transfer of blood or any of its parts to a person who has lost blood due to an injury, disease, or operation

Blood type- a category used to describe a person's blood according to the kinds of proteins present on the surface of the red blood cells B lymphocyte- a type of white blood cell that makes antibodies and is an important part of the immune response

Boil- an inflamed, raised area of skin that is pus-filled; usually an infected hair follicle

Bone marrow- the fatty yellow or red tissue inside bones that is responsible for producing blood cells

Bone marrow transplant- a surgical procedure in which defective or cancerous bone marrow is replaced with healthy marrow, either from the patient or a donor

Bone spur- an abnormal growth of bone out of another bone, often located on the heel and usually painful

Booster- an additional dose of a vaccine taken after the first dose to maintain or renew the first one

Botulism- poisoning from poorly preserved food contaminated with a dangerous bacterial toxin that results in paralysis

Bowel- see Intestine Bradycardia- a slow heart rate, usually below 60 beats per minute in adults

Brain damage- permanent death or damage of brain cells resulting in decreased mental ability

Brain death- the condition in which the brain stops functioning while the heart continues to beat

Breech birth- childbirth in which the baby is turned around in the uterus and emerges head-last instead of head-first

Bronchiolitis- an infection caused by a virus in the bronchioles (the smallest airways in the lungs), mainly affecting young children

Bronchitis- inflammation of the bronchial tubes, which connect the trachea to the lungs

Bronchoconstrictor- a substance that causes the lung airways to tighten up and become more narrow

Bronchodilator- a drug that widens the airways in the lungs to improve breathing; works by relieving muscle contraction or buildup of mucus

Bronchospasm- the temporary narrowing of the airways in the lungs, either as a result of muscle contraction or inflammation; may be caused by asthma, infection, lung disease, or an allergic reaction

Bruise- see Contusion

Bruxism- an unaware clenching or grinding of the teeth, usually during sleep

Bubonic plague- a form of plague in which lymph nodes in the groin and armpit swell

Bulimia- a disorder in which a person eats large amounts of food then forces vomiting or uses laxatives to prevent weight gain (called binging and purging)

Bunion- a hard, fluid-filled pad along the inside joint of the big toe; may be caused by wearing high-heeled shoes or a genetically weak joint

Burkitt's lymphoma- a cancer of lymph tissue that most frequently occurs in the abdomen, the ovaries, and the bones of the face; it is associated with malaria Bursa- a fluid-filled sac that cushions and reduces friction in certain parts of the body

Bursitis- inflammation of a bursa due to excessive pressure or friction, or from injury

Butterfly bandage- a butterfly-shaped bandage that can help close a minor cut for proper healing

Bypass- a surgical technique in which the flow of blood or another body fluid is redirected around a blockage

C

Calcification- the depositing of calcium salts in the body, which occurs normally in teeth and bones but abnormally in injured muscles and narrowed arteries

Calcitonin- a hormone made in the thyroid gland that controls calcium levels in the blood by slowing the loss of calcium from bones; used to treat hypercalcemia (excess calcium in the blood)

Calcium- a plentiful mineral in the body and the basic component of teeth and bones; essential for cell function, muscle contraction, transmission of nerve impulses, and blood clotting

Calcium channel blocker- a drug used to treat chest pain, high blood pressure, and irregular heartbeat by preventing the movement of calcium into the muscle

Callus- a thickened area of skin due to consistent pressure or friction, or the area around a bone break where new bone is formed

Calorie- a unit that is used to measure the energy content in food

Canal- a tunnel-like passage

Cancer- a group of diseases in which cells grow unrestrained in an organ or tissue in the body; can spread to tissues around it and destroy them or be transported through blood or lymph pathways to other parts of the body

Cancer staging- a method to determine how much a cancer has developed

Candidiasis- a yeast infection caused by the fungus Candida albicans; occurs most often in the vagina, but also in the mouth, on moist skin, or on the penis

Canker sore- small, painful sore that usually occurs on the inside of the lip or cheek, or sometimes under the tongue; caused by bacteria, irritation of the area, stress, or allergies

Capillary- a tiny blood vessel that connects the smallest arteries to the smallest veins and allows exchange of oxygen and other materials between blood cells and body tissue cells

Carbohydrate- a substance, mainly sugar and starch, that is a main source of energy for the body and is found in sources such as cereals, breads, pastas, grains, and vegetables

Carbon dioxide- a colorless, odorless gas present in small amounts in the atmosphere and formed during respiration

Carcinogen- anything that can cause cancer

Carcinoma- a cancer that occurs on the surface or lining of an organ

Cardiac arrest- the sudden cessation of the heart's pumping action, possibly due to a heart attack, respiratory arrest, electrical shock, extreme cold, blood loss, drug overdose, or a severe allergic reaction

Cardiogenic shock- a severely dangerous condition involving decreased blood output from the heart, usually as a result of a heart attack

Cardiomegaly- a condition marked by enlargement of the heart, either because of a thickened heart muscle or an enlarged heart chamber; usually a result of the heart having to work harder than normal, as occurs with high blood pressure

Cardiomyopathy- a disease of the heart muscle that results in decreased output and reduced blood flow

Cardiopulmonary resuscitation- the administration of heart compression and artificial respiration to restore circulation and breathing

Cardiovascular system- the heart and blood vessels that are responsible for circulating blood throughout the body

Carditis- inflammation of the heart

Carotene- an orange pigment present in colored plants such as carrots that is converted by the body to the essential nutrient vitamin A Carotid arteries- four main arteries that carry blood to the head and neck

Carpal bones- eight bones that together make the wrist

Carpal tunnel syndrome- a condition in which pressure on the median nerve in the wrist causes soreness, tingling, and numbness in the thumb and index and middle fingers

Cartilage- a connective tissue (softer than bone) that is part of the skeletal system, including the joints

Cast- a hard plaster or fiberglass shell that molds to a body part such as an arm and holds it in place for proper healing

Cataract- a disorder in which the lens of the eye becomes less transparent and in some cases a milky white, making vision less clear

Catheter- a hollow, flexible tube inserted into the body to put in or take out fluid, or to open up or close blood vessels

Catheterization- a technique in which a hollow, flexible tube is used to drain body fluids (such as urine), to introduce fluids into the body, or to examine or widen a narrowed vein or artery

CAT scanning- see Computed tomography scanning

Cat-scratch fever- an illness transmitted to humans through a cat's bite or scratch, which is thought to be caused by an unidentified bacteria; characterized by a swollen lymph node or blister near the bite or scratch, fever, rash, and headache; most commonly occurring in children

Cauliflower ear- a deformed ear caused by repeated injury

Cauterization- the use of heat, an electric current, or a chemical to destroy tissue or stop bleeding

Cecum- the beginning of the large intestine, which is connected to the appendix at its lower end

Cell- the tiny structures that make up all the tissues of the body and carry out all of its functions

Cellulitis- a skin infection caused by bacteria (usually streptococci); can lead to tissue damage and blood poisoning if untreated; characterized by fever, chills, heat, tenderness, and redness

Central nervous system- the brain and spinal cord

Cerebellum- a region of the brain located at the back; responsible for coordination of movement and maintaining balance

Cerebral palsy- a group of disorders of movement and posture resulting from damage to the brain early in a child's development; causes muscle weakness, difficulty coordinating voluntary movements, and sometimes complete loss of motion

Cerebrospinal fluid- a clear, watery fluid circulating in and around the brain and spinal column, which contains glucose, proteins, and salts for nutrition

Cerebrovascular disease- a disease affecting any artery supplying blood to the brain; may cause blockage or rupture of a blood vessel, leading to a stroke

Cerebrum- the largest part of the brain and the site of most of its activity, including sensory and motor functions

Cervical cap- a small rubber cup that is placed tightly over the cervix to prevent pregnancy

Cervical dysplasia- changes that occur in the cells on the surface of the cervix that usually precede the stages of cancer

Cervical incompetence- a weakness of the neck of the uterus, which can lead to spontaneous abortion due to an inability to support the weight of the fetus

Cervical smear- a procedure in which cells are scraped off of the cervix and examined to detect changes that might precede the stages of cancer; also called a Pap smear

Cervicitis- inflammation of the cervix

Cervix- a small, round organ making up the neck of the uterus and separating it from the vagina

Cesarean section- an operation performed to remove a fetus by cutting into the uterus, usually through the abdominal wall

Chancre- a painless sore that has a thick, rubbery base and a defined edge; usually occurs on the genitals after the contraction of the sexually transmitted disease syphilis

Chemotherapy- the treatment of infections or cancer with drugs that act on disease-producing organisms or cancerous tissue; may also affect normal cells

Chickenpox- a contagious disease that causes a rash and a fever; most commonly occurs during childhood

Chlamydia- microorganisms that cause several human infections and can be transmitted sexually

Cholecystectomy- the surgical removal of the gallbladder

Cholera- a bacterial infection of the small intestine that causes severe watery diarrhea, dehydration, and possibly death

Cholesterol- a substance in body cells that plays a role in the production of hormones and bile salts and in the transport of fats in the bloodstream

Chondritis- inflammation of cartilage

Chondroma- a noncancerous tumor that occurs in cartilage

Chondromalacia patellae- painful damage to the cartilage behind the kneecap

Chondrosarcoma- a cancerous cartilage tumor that develops inside of bone or on its surface

Chorionic villus sampling- a method of diagnosing fetal defects in which a small amount of tissue is taken from the placenta and analyzed for abnormalities

Choroiditis- inflammation of the blood vessels behind the retina that line the back of the eye

Chromosome analysis- examination of a person’s chromosomes either to determine if that person has an abnormality or to investigate one

Chronic- describes a disorder that continues for a long period of time Chronic obstructive lung disease- a combination of the lung diseases emphysema and bronchitis, characterized by blockage of airflow in and out of the lungs

Cilia- tiny, hairlike structures on the outside of some cells, providing mobility

Circumcision- the surgical removal of the foreskin of the penis

Cirrhosis of the liver- gradual loss of liver function due to cell damage and internal scarring

Claudication- a cramping pain in one or both legs while walking, which can cause limping

Claustrophobia- fear of being confined in an enclosed or crowded space

Clavicle- the medical term for the collarbone

Cleft lip- a birth defect in which the upper lip is split vertically, extending into one or both nostrils

Cleft palate- a birth defect in which the roof of the mouth is split, extending from behind the teeth to the nasal cavity; often occurs with other birth defects such as cleft lip and partial deafness

Clinical trial- carefully monitored and planned testing of a new drug or treatment

Clitoris- a small female organ located near the opening of the vagina that swells when sexually aroused

Clone- an exact copy of a gene, cell, or organism

Closed fracture- a bone break that does not break the skin

Clotting factor- a substance in the blood that is needed for blood to harden and stop a wound from bleeding

Clubfoot- a genetic disorder in which the foot is twisted and misshapen

Cluster headache- severe pain that occurs suddenly and affects one side of the head, including the face and neck

CNS- see Central nervous system

Coagulation- a process that plays a large role in the hardening and thickening of blood to form a clot

Cocarcinogen- a substance that does not cause cancer by itself, but increases the effect of a substance that does cause cancer

Coccyx- four fused bones that form a triangular shape at the base of the spine (also known as the tailbone)

Cochlea- a coiled organ in the inner ear that plays a large role in hearing by picking up sound vibrations and transmitting them as electrical signals

Coitus- sexual intercourse

Cold sore- a small blister anywhere around the mouth that is caused by the herpes simplex virus

Colectomy- the complete or partial surgical removal of the large intestine (the colon), usually as treatment of a cancerous tumor or a narrowing and blockage of the intestine

Colic- waves of pain in the abdomen that increase in strength, disappear, and return; usually caused by a stone blocking a bile or urine passageway or an intestinal infection

Colitis- inflammation of the large intestine (the colon), which usually leads to abdominal pain, fever, and diarrhea with blood and mucus

Collapsed lung- a condition in which all or part of a lung cannot expand and fill with air

Colon- the main part of the large intestine, between the cecum and the rectum

Colonoscopy- investigation of the inside of the colon using a long, flexible fiberoptic tube

Color blindness- any vision disorder in which the person sees colors abnormally, has trouble distinguishing between them, or cannot see them at all

Colostomy- a surgical procedure in which some part of the colon is cut and moved to the surface of the abdomen so that feces can be passed into a bag worn outside of the body

Coma- a condition in which the area of the brain involved in maintaining consciousness is somehow affected, resulting in a state of unconsciousness in which the patient does not respond to stimulation

Comminuted fracture- a crushed or shattered bone

Common cold- an infection caused by a virus, which results in an inflamed lining of the nose and throat; characterized by a stuffy and runny nose and, sometimes, a sore throat

Communicable disease- a disease that can be passed from one individual to another

Compound fracture- a bone break that breaks the skin

Compression fracture- a break in a short bone in which its soft tissue is crushed

Computed tomography scanning- a technique for producing cross-sectional images of the body in which X-rays are passed through the body at different angles and analyzed by a computer; also called CT scanning or CAT scanning

Concussion- disturbance of electrical activity in the brain due to a blow to the head or neck, causing temporary loss of consciousness

Congenital- present or existing at the time of birth Congestive heart failure- inability of the heart to efficiently pump blood through the body, causing buildup of blood in the veins and of other body fluids in tissue

Conjunctiva- the clear membrane covering the white of the eye and the inside of the eyelid that produces a fluid that lubricates the cornea and eyelid

Conjunctivitis- inflammation of the conjunctiva; commonly called pinkeye

Connective tissue- strong tissue that connects and supports body structures

Constipation- difficult or infrequent bowel movements of hard, dry feces

Contraindication- an aspect of a patient's condition that makes the use of a certain drug or therapy an unwise or dangerous decision

Contusion- damage to the skin and underlying tissue as a result of a blunt injury; a bruise

Corn- a thickened callus on the foot that is caused by an improperly fitting shoe

Cornea- the clear, dome-shaped front portion of the eye’s outer covering

Coronary- describes structures that encircle another structure (such as the coronary arteries, which circle the heart); commonly used to refer to a coronary thrombosis or a heart attack

Coronary arteries- the arteries that branch off from the aorta and supply oxygen-rich blood to the heart muscle

Coronary artery bypass surgery- an operation in which a piece of vein or artery is used to bypass a blockage in a coronary artery; performed to prevent myocardial infarction and relieve angina pectoris

Coronary heart disease- disorders that restrict the blood supply to the heart, including atherosclerosis

Coronary thrombosis- the blockage of a coronary artery by a blood clot Corpuscle- a tiny, rounded structure in the body, such as a red or white blood cell

Corticosteroids- synthetic drugs that are used to replace natural hormones or to suppress the immune system and help prevent inflammation

CPR- see Cardiopulmonary resuscitation

Creatinine- a waste product that is filtered from the blood by the kidneys and expelled in urine

Croup- a usually mild and temporary condition common in children under the age of 4 in which the walls of the airways become inflamed and narrow, resulting in wheezing and coughing

Cruciate ligaments- two ligaments in the knee that cross each other and help stabilize the knee joint

CT scanning- a procedure that uses X-rays and computers to create cross-sectional images of the body to diagnose and monitor disease

Culture- the artificial growth of cells, tissue, or microorganisms such as bacteria in a laboratory

Curettage- the use of a sharp, spoonlike instrument (a curet) to scrape away tissue that is abnormal or to obtain a sample that can be analyzed

CVS- see Chorionic villus sampling

Cyanosis- a bluish discoloration of the skin, caused by low levels of oxygen in the blood

Cyst- a lump filled with either fluid or soft material, occurring in any organ or tissue; may occur for a number of reasons but is usually harmless unless its presence disrupts organ or tissue function

Cystectomy- surgical removal of the bladder; the bladder is often replaced with a short length of small intestine

Cystic fibrosis- an inherited disorder in which the lungs are prone to infection, and fats and other nutrients cannot be absorbed into the body

Cystoscopy- examination of the urethra and bladder using a long, thin, fiberoptic tube

Cystostomy- the surgical placement of a drainage opening in the bladder

D

D and C- see Dilatation and Curettage

Debridement- surgical removal of dead, damaged, or infected tissue, or some foreign material from a wound or burn

Decompression sickness- the formation of gas bubbles in the body’s tissues as a result of a scuba diver ascending too quickly from depth; commonly called the bends

Deep-vein thrombosis- the formation of a blood clot inside of a deep-lying vein, usually in the legs

Defecation- the passing of feces out of the body through the anus; a bowel movement

Defibrillation- a short electric shock to the chest to normalize an irregular heartbeat

Degenerative arthritis- the breakdown of the cartilage lining the bones in joints, usually weight-bearing joints (such as the knee); causes stiffness and pain (also called osteoarthritis)

Dehydration- excessive, dangerous loss of water from the body

Dementia- a gradual decline in mental ability usually caused by a brain disease, such as Alzheimer disease

Depilatory- a chemical hair remover

Depot injection- injection of a drug into a muscle; the drug is designed to absorb slowly into the body

Depression- feelings of hopelessness, sadness, and a general disinterest in life, which for the most part have no cause and may be the result of a psychiatric illness

Dermabrasion- removal of the surface layer of skin with a sanding wheel to treat scarring or to remove tattoos

Dermatitis- inflammation of the skin

Dermis- the inner skin layer

Desensitization- the process of making a person less allergic to a substance by injecting gradually increasing amounts of the substance; sometimes done to prevent anaphylactic shock

Detoxification- treatment given either to fight a person's dependence on alcohol or other drugs or to rid the body of a poisonous substance and its effects

Dextrocardia- a rare genetic condition in which the heart is located on the right side of the body, instead of the left

Dextrose- another name for the sugar glucose

Diabetes insipidus- a rare condition characterized by increased urine production

Diabetes mellitus- a common form of diabetes in which the body cannot properly store or use glucose (sugar), the body's main source of energy

Dialysis- a procedure to treat kidney failure in which artificial means are used to filter waste, maintain acid-base balance, and remove excess fluid from the body

Diaper rash- a common condition in babies in which the skin in the diaper area becomes irritated and red, usually because of exposure to urine, feces, or heat

Diaphragm- the large, dome-shaped muscle separating the abdomen and chest that contracts and relaxes to make breathing possible; also, a thin, rubber dome that is used as a method of female contraception

Diastolic pressure- the blood pressure measured when the heart is at rest between beats

Diathermy- the use of high-frequency currents, microwaves, or ultrasound to produce heat in the body to increase blood flow, relieve pain, or destroy diseased tissue

Dilatation and Curettage- a procedure in which the vagina and cervix are widened and the lining of the uterus is scraped away to diagnose and treat disorders of the uterus

Diphtheria- a bacterial infection that causes a fever, headache, sore throat, and possibly death; diphtheria is rare in developed countries

Disk prolapse- a disorder in which one of the disks located between the vertebrae in the spine breaks down and the pulpy interior squeezes out, causing pressure on a nerve; commonly called a "slipped" or "ruptured" disk

Dislocation- displacement of the two bones in a joint

Distention- swelling, enlargement, or stretching

Diuretic- a drug that increases the amount of water in the urine, removing excess water from the body; used in treating high blood pressure and fluid retention

Diverticulitis- inflammation of diverticula (small sacs in the intestine's inner lining); can cause fever, pain, and tenderness

DNA- deoxyribonucleic acid; responsible for passing genetic information in nearly all organisms

Dominant gene- a gene that always produces its effect when it is present

Dopamine- a chemical that transmits messages in the brain and plays a role in movement

Down syndrome- a genetic disorder in which a person’s cells have 1 too many chromosomes, causing moderate to severe mental handicap and a characteristic appearance

Duchenne muscular dystrophy- a genetic condition in boys in which nerves degenerate and muscles get progressively weaker

Duodenal ulcer- an erosion in the inner lining of the wall of the first part of the small intestine (called the duodenum)

Duodenum- the first part of the small intestine, immediately following the stomach

Dysentery- a severe intestinal infection, causing abdominal pain and diarrhea with blood or mucus

Dyspnea- difficulty breathing

Dystrophy- any disorder in which cells become damaged or do not develop properly because they do not receive adequate nutrition

E

Eardrum- a thin, oval-shaped membrane that separates the inner ear from the outer ear and is responsible for transmitting sound waves

ECG (sometimes called an EKG)- an electrocardiogram, which is a record of the electrical impulses that trigger the heartbeat; used to diagnose heart disorders

Echocardiogram- an image of the heart that is created by high-frequency (ultrasound) sound waves

Eclampsia- a serious condition that occurs in late pregnancy, characterized by seizures in the woman

Ectopic- occurring at an abnormal position or time

Eczema- inflammation of the skin, usually causing itchiness and sometimes blisters and scaling; may be caused by allergies, but often occurs for no apparent reason

Edema- abnormal buildup of fluid in the body, which may cause visible swelling

EEG- see Electroencephalography

Elective- describes a treatment or procedure that is not urgent and can be arranged at the patient’s convenience

Electroencephalography- a procedure for recording the electrical impulses of brain activity

Embolism- the blockage of a blood vessel by an embolus - something previously circulating in the blood (such as a blood clot, gas bubble, tissue, bacteria, bone marrow, cholesterol, fat, etc)

Embryo- a term used to describe a child in the womb from fertilization to 8 weeks following fertilization

Emetic- a substance that causes vomiting; used to treat some cases of poisoning and drug overdose

Emphysema- a chronic disease in which the small air sacs in the lungs (the alveoli) become damaged; characterized by difficulty breathing

Encephalitis- inflammation of the brain, usually caused by a virus; may be very mild and barely noticeable, but is usually serious and can progress from headache and fever to hallucinations, paralysis, and sometimes coma

Endarterectomy- surgery performed to remove the lining of an artery that has been narrowed by fatty tissue buildup

Endemic- describes a disease that is always present in a certain population of people

Endocarditis- inflammation of the inner lining of the heart, usually the heart valves; typically caused by an infection

Endocardium- the inner lining of the heart

Endocrine gland- a gland that secretes hormones into the bloodstream

Endogenous- arising from inside of the body

Endometrial polyp- a growth (usually noncancerous) occurring on the lining of the uterus

Endometriosis- a condition in which fragments of the endometrium are found in other pelvic organs

Endometrium- the membrane that lines the uterus

Endophthalmitis- inflammation of the inside of the eye

Endorphin- a group of chemicals produced in the brain that reduce pain and positively affect mood

Endoscope- a lighted instrument used to view the inside of a body cavity

Endothelium- the layer of flat cells that lines the blood and lymph vessels, the heart, and other structures in the body

Endotracheal tube- a plastic tube that is fed down into the trachea through the mouth or nose to supply oxygen to a person who is not breathing properly

Enteritis- inflammation of the small intestine, usually causing diarrhea

Enterobiasis- infestation by a pinworm

Enuresis- the medical term for wetting the bed

Enzyme- a chemical, originating in a cell, that regulates reactions in the body

Epidemic- a term used to describe a disease that is rare then suddenly affects more people than usually expected

Epidermis- the outer layer of the skin

Epididymis- a long, coiled tube, exiting from the back of the testicle, in which sperm mature

Epidural anesthesia- a method of pain relief in which a painkilling drug is injected into the space surrounding the spinal cord to block sensations in the abdomen and lower body

Epilepsy- a disorder of the nervous system in which abnormal electrical activity in the brain causes seizures

Epinephrine- a hormone produced by the adrenal glands in response to stress, exercise, or fear; increases heart rate and opens airways to improve breathing; also called adrenaline

Episcleritis- a patch of inflammation on the outer layer of the white of the eye

Episiotomy- a surgical procedure in which an incision is made in the tissue between the vagina and anus to prevent tearing of this tissue during childbirth

Epithelium- the layer of cells that covers the body and lines many organs

Epstein-Barr virus- a virus that is the cause of mononucleosis and is involved in Burkitt’s lymphoma

Erysipelas- an infection caused by streptococci bacteria; characterized by fever and rash

Erythema- redness of the skin

Erythrocyte- a red blood cell

Erythrocyte sedimentation rate- a measure of the time it takes for red blood cells to collect at the bottom of a sample of blood; an elevated rate may mean that there is inflammation somewhere in the body

Erythroplakia- red patches in the mucous membranes of the mouth, throat, or voice box (larynx) that can become cancerous; risk factors include smoking pipes and chewing tobacco

Esophageal spasm- irregular contractions of the muscles in the esophagus, which lead to difficulty swallowing

Esophageal varices- swollen veins in the lower esophagus and possibly the upper part of the stomach; can cause vomiting of blood and passing of black stool

Esophagus- a tube-shaped canal in the digestive tract, connecting the throat to the stomach

Estrogen- a group of hormones (produced mainly in the ovaries) that are necessary for female sexual development and reproductive functioning

Estrogen replacement therapy- treatment with synthetic estrogen drugs to relieve symptoms of menopause and to help protect women against osteoporosis and heart disease

Eustachian tube- the tube that connects the middle ear and the back of the nose, draining the middle ear and regulating air pressure

Euthanasia- painlessly ending the life of a patient with an incurable disease who requests to die

Excision- the surgical removal of diseased tissue

Excretion- the process by which the body rids itself of waste

Exercise stress test- the monitoring of the heart during strenuous exercise, usually on a treadmill or exercise bicycle, to evaluate how the heart responds to stress

Exercise thallium test- an imaging test performed during and after an exercise stress test to evaluate functioning of the heart muscles

Exogenous- arising from outside of the body

Expectorant- a medication used to promote the coughing up of phlegm from the respiratory tract

Extensor muscle- a muscle that causes a joint or limb to straighten

External version- external repositioning of the fetus in the womb to the correct birth position

Extracorporeal shock wave lithotripsy- a procedure performed to destroy kidney stones using external shock waves

Extradural anesthesia- injection of an anesthetic into the space outside the dura mater, the fibrous membrane that envelops the spinal cord

F

Facial palsy- inability to move the muscles of the face, usually on only one side, due to inflammation of a nerve

Failure to thrive- describes a baby who grows and gains weight slower than expected

Fallopian tube- either of two long, slender ducts connecting a woman's uterus to her ovaries, where eggs are transported from the ovaries to the uterus and sperm may fertilize an egg

Familial- a term describing a disorder or characteristic (such as male pattern baldness) that occurs within a family more often than would be expected

Fasciitis- inflammation of the layer of connective tissue that covers, separates, and supports muscles

Fatty acid- any of a number of carbon-, oxygen-, and hydrogen-containing molecules that make up fats

Febrile- a term used to describe something related to a fever, such as febrile seizures (seizures occurring in a child who has a fever)

Fecal occult blood test- a test that uses a piece of chemically sensitive paper to detect blood in a stool sample; used to screen for possible signs of cancer in the large intestine or rectum

Femoral artery- the main artery that supplies blood to the leg

Femur- the bone located between the hip and the knee; the thighbone

Fertility- the ability to produce a child

Fertility drug- a drug used to treat infertility that contains hormones or substances associated with hormones

Fertilization- the joining of an egg and a sperm, creating the first cell of a new life

Fetal alcohol syndrome- a combination of defects in a fetus as a result of the mother drinking alcohol during pregnancy

Fetal distress- physical distress experiencd by a fetus because of lack of oxygen

Fetal monitoring- the use of an instrument to record or listen to a fetus' heartbeat during pregnancy and labor

Fetal tissue transplant- an experimental procedure in which cells are taken from an aborted fetus and placed into the brain of a person with a brain disease such as Parkinson's

Fetus- the term used to refer to an unborn child from 8 weeks after fertilization to birth

Fiber- a constituent of plants that cannot be digested, which helps maintain healthy functioning of the bowels

Fiberoptics- thin, flexible instruments that transmit light and images, allowing structures inside of the body to be viewed

Fibrillation- rapid, inefficient contraction of muscle fibers of the heart caused by disruption of nerve impulses

Fibroadenoma- a noncancerous tumor commonly found in the breast

Fibrocystic breast disease- the most common cause of breast lumps

Fibroid- a noncancerous tumor of the uterus made up of smooth muscle and connective tissue

Fibroma- a noncancerous tumor of connective tissue

Fibrosis- abnormal formation of connective or scar tissue

Fifth disease- a childhood infection caused by a virus, which often starts as a rash on the cheeks and spreads

Fissure- a groove or slit on the body or in an organ

Fistula- an abnormal passageway from one organ to another or from an organ to the body surface

Fitness- a measure of a person's physical strength, flexibility, and endurance

Flatulence- excessive air or gas in the intestines, which is expelled through the anus

Floaters- small spots that float across the field of vision, caused by debris floating in the gel-like substance that fills the eye

Flu- see Influenza

Fluke- a parasitic flatworm that can infest humans

Fluoride- a mineral that helps protect teeth against decay

Fluoroscopy- a method used to view organ structure and function by passing X-rays through the body and monitoring the resulting image on a fluorescent screen

Folic acid- a vitamin essential to the production of red blood cells; plays an important role in the growth a developing fetus

Follicle- a tiny pouchlike cavity in a structure of the body, such as a hair follicle Follicle stimulating hormone- a hormone produced by the pituitary gland in the brain that stimulates the testicles to produce sperm in males and causes eggs to mature in females

Folliculitis- the inflammation of hair follicles due to a bacterial infection, causing boils or tiny blisters containing pus

Fontanelles- the two soft spots on a baby’s scalp that are the result of gaps in the skull where bones have not yet fused

Food poisoning- stomach pain, diarrhea, and/or vomiting caused by eating contaminated food

Forceps- instruments resembling tweezers that are used to handle objects or tissue during surgery

Forceps delivery- the use of an instrument that cups the baby's head (called an obstetric forceps), to help deliver a baby

Foreign body- an object in an organ or body cavity that is not normally present

Foreskin- the loose skin that covers the head of the penis

Fracture- a bone break

Fraternal twins- twins that develop from two different eggs fertilized by two different sperm; are not identical

Free radical- see Oxygen free radical

Frostbite- damage to body tissue as a result of freezing

FSH- see Follicle stimulating hormone

Fulminant- describes a disorder that begins suddenly and worsens quickly

Fungus- an organism that is dependent on another organism for nourishment

G

Galactocele- a milk-filled tumor in a blocked breast milk duct

Galactorrhea- breast milk production by a woman who is not pregnant and has not just given birth

Galactose- a sugar that is formed from the breakdown of lactose

Galactosemia- a genetic disorder in which galactose cannot be converted into glucose

Gallbladder- a small, pear-shaped sac positioned under the liver, which concentrates and stores bile

Gallstone- a round, hard mass of cholesterol, bile, or calcium salts that is found in the gallbladder or a bile duct

Gallstone ileus- an abnormal condition in which a gallstone passes from the gallbladder into the intestines through an abnormal passage and blocks the intestine

Gamete intrafallopian transfer- a method of treating infertility in which eggs are taken from a woman's ovaries and fertilized with sperm and then the fertilized egg is injected into one of her fallopian tubes

Gamma globulin- a substance prepared from blood that carries antibodies to most common infections; also used in immunizations

Ganglion- a fluid-filled cyst attached to a tendon sheath or joint

Gangrene- death of a tissue because of a lack of blood supply

Gastrectomy- surgical removal of all or part of the stomach

Gastric acid- the digestive acid in the stomach

Gastric juice- digestive fluids produced by the lining of the stomach that break down proteins and destroy harmful organisms

Gastric lavage- washing out of the stomach with water, often to treat poisoning; commonly called "stomach pumping"

Gastric ulcer- a peptic ulcer

Gastrin- a hormone that stimulates the release of gastric acid in the stomach

Gastrinoma- a tumor that produces gastrin, making the stomach and duodenum more acidic

Gastritis- inflammation of the mucous membrane lining of the stomach; can have a number of causes, including viruses, bacteria, and use of alcohol and other drugs

Gastroenteritis- inflammation of the stomach and intestines

Gastrointestinal series- a set of X-rays, taken at different intervals after a barium sulfate solution is swallowed, to examine the gastrointestinal tract

Gastrointestinal tract- the part of the digestive system that includes the mouth, esophagus, stomach, and intestines

Gastroscopy- examination of the esophagus, stomach, and the first part of the small intestine (duodenum) using an endoscope inserted through the mouth

Gastrostomy- the surgical creation of an opening in the abdominal wall into the stomach for drainage or a feeding tube

Gaucher’s disease- a genetic disorder in which lipids cannot be properly broken down and build up in certain cells; causes enlargement of the spleen and liver, bone damage, and anemia

Gavage- an artificial feeding technique in which liquids are passed into the stomach by way of a tube inserted through the nose

Gene- the basic unit of DNA, which is responsible for passing genetic information; each gene contains the instructions for the production of a certain protein

General anesthesia- a method of preventing pain in which the patient is induced to lose consciousness

Generic drug- a drug marketed under its chemical name, instead of a brand name

Gene therapy- an experimental procedure in which disease-causing genes are replaced by normal, healthy genes

Genetic analysis- examination of DNA in a laboratory to diagnose genetic disorders

Genetic counseling- information and advice given to persons considering pregnancy about the risk that a child will have an inheritable birth defect or genetic disorder

Genetic disorder- a disorder caused partly or completely by a defect in genes, which carry hereditary information

Genetic engineering- the alteration of genetic information to change an organism; mainly used to produce vaccines and drugs such as insulin

Genital herpes- an infection caused by the herpes simplex virus, which causes a painful rash of fluid-filled blisters on the genitals; transmitted through sexual contact

Genital tract- the organs that make up the reproductive system

Genital wart- a growth on the skin in or around the vagina, penis, or anus, transmitted by sexual contact; can cause cancer of the cervix

Genome- the complete set of an organism’s genes Geographic tongue- a condition in which the tongue is patchy where surface cells break down

German measles- the common name for Rubella

Germ cell- a sperm or egg cell, or the immature form of either

Gestation- the period of time between fertilization of an egg by a sperm and birth of a baby

Giardiasis- infection with a single-celled parasite, causing abdominal cramps, diarrhea, and nausea

GIFT- see Gamete intrafallopian transfer

Gingivectomy- surgical removal of a diseased part of the gums

Gingivitis- inflammation of the gums, typically caused by a buildup of plaque due to poor hygiene

GI series- see Gastrointestinal series

Gland- a group of cells or an organ that produces substances (such as hormones and enzyme) that are used by the body

Glaucoma- a disease in which eye damage is caused by an increase in the pressure of the fluid within the eye

Glioblastoma multiforme- a fast-growing, cancerous brain tumor

Glioma- a brain tumor arising from cells that support nerve cells

Glomerulonephritis- inflammation of the filtering structures in the kidneys, hindering removal of waste products from the blood

Glomerulosclerosis- scarring of the filtering structures in the kidneys due to damage

Glossectomy- surgical removal of all or part of the tongue

Glucagon- a hormone produced by the pancreas that converts stored carbohydrates (glycogen) into glucose, the body’s energy source

Glucose- a sugar that is the main source of energy for the body

Glucose tolerance test- a test that evaluates the body's response to glucose after a period of fasting; used to check for diabetes mellitus

Glycogen- the main form that glucose, the body’s energy source, takes when it is stored

Glycosuria- glucose in the urine

Goiter- enlargement of the thyroid gland, which produces a swelling on the neck

Gonadotropic hormones- hormones that stimulate activity in the ovaries and testicles

Gonorrhea- a common sexually transmitted disease, characterized by painful urination or a discharge from the penis or vagina

Gout- a disorder marked by high levels of uric acid in the blood; usually experienced as arthritis in one joint

Graft- healthy tissue that is used to replace diseased or defective tissue

Grand mal- a type of seizure occurring with epilepsy, producing loss of consciousness and involuntary jerking movements

Granuloma- a mass of tissue that forms at a site of inflammation, injury, or infection as a part of the healing process

Graves' disease- an autoimmune disease that causes goiter, overproduction of thyroid hormones, and sometimes bulging eyeballs

Guillain-Barré syndrome- a peripheral nervous system disease in which nerve inflammation causes weakness, loss of movement, and loss of sensation in the arms and legs

Guthrie test- a blood test performed on babies to test for phenylketonuria

H

Hair follicle- a tiny opening in the skin from which a hair grows

Halitosis- the clinical term for bad breath; commonly caused by poor oral hygiene or eating certain foods; if persistent it can be a sign of illness

Hallucination- a perception that occurs when there is actually nothing there to cause it (such as hearing voices when there are none)

Hammer toe- an abnormality in the tendons of the toe that causes the toe to be flexed at all times

Hamstring muscle- a muscle located at the back of the thigh that bends the leg at the knee and moves the leg backward

Hardening of the arteries- the common name for arteriosclerosis

Hashimoto’s disease- a disease in which the body’s immune system attacks cells of the thyroid gland, resulting in a decrease in thyroid hormones

Hay fever- the common name for allergic rhinitis

HDL- see High-density lipoprotein

Heart attack- see Myocardial infarction

Heart block- a disorder of the heart caused by a blockage of the nerve impulses to the heart that regulate heartbeat; may lead to dizziness, fainting, or stroke

Heartburn- a burning sensation experienced in the center of the chest up to the throat; may be caused by overeating, eating spicy food, or drinking alcohol; recurrent heartburn may be caused by acid reflux

Heart disease- see Coronary heart disease

Heart failure- the inability of the heart to pump blood effectively

Heart-lung machine- a machine that takes over the functions of the heart and lungs during certain types of surgery

Heart rate- the rate at which the heart pumps blood, measured in the number of heartbeats per minute

Heart valve- the structure at each exit of the four chambers of the heart that allows blood to exit but not to flow back in

Heat exhaustion- fatigue, dizziness, and nausea experienced because of overexposure to heat; if not treated it can result in heat stroke

Heat stroke- a life-threatening condition resulting from extreme overexposure to heat, which disrupts the body's system of regulating temperature

Heel spur- an abnormal, often painful outgrowth of bone on the back of the heel

Heimlich maneuver- a first-aid technique for choking; dislodges an object that is blocking a person’s airway

Helper T cells- white blood cells, responsible for regulating other cells in the body's immune system, that are the main targets of the AIDS virus; also called CD4 cells

Hemangioma- a purple-red mark on the skin, caused by an excess of blood vessels

Hemarthrosis- bleeding into and swelling of a joint

Hematemesis- vomiting of blood

Hematocrit- the percentage of total blood volume that consists of red blood cells, which is determined by laboratory testing; can be an indicator of disease or injury

Hematoma- an accumulation of blood from a broken blood vessel

Hematuria- blood in the urine, which can be caused by urinary tract disorders (such as cysts, tumor, or stones) or by an infection

Hemochromatosis- a genetic disorder in which too much iron is absorbed from food

Hemodialysis- a method used to treat kidney failure, in which blood is passed through a machine that purifies it and returns it to the body

Hemoglobin- the pigment in red blood cells that is responsible for carrying oxygen; hemoglobin bound to oxygen gives blood its red color

Hemoglobinuria- hemoglobin in the urine

Hemolysis- the breakdown of red blood cells in the spleen, which is normal but can cause jaundice and anemia when the red blood cells are broken down too quickly

Hemophilia- an inherited disorder in which a person's blood lacks a certain protein important in forming blood clots, leading to excessive bleeding

Hemorrhage- the medical term for bleeding

Hemorrhoid- a bulging vein either at the opening of the anus or just inside the anus, often caused by childbirth or straining during bowel movements

Hemospermia- blood in the semen

Hemostasis- the stopping of bleeding by the body’s mechanisms

Hemothorax- an accumulation of blood between the chest wall and the lungs

Hepatectomy- surgical removal of all or part of the liver

Hepatic- a term used to describe something that is related to the liver

Hepatitis- inflammation of the liver, which may be caused by a viral infection, poisons, or the use of alcohol or other drugs

Hepatitis A- a form of hepatitis caused by the hepatitis A virus, usually transmitted by contact with contaminated food or water

Hepatitis B- a form of hepatitis (generally more serious than hepatitis A) caused by the hepatitis B virus, which is transmitted through sexual contact or contact with infected blood or body fluids

Hepatitis C- a form of hepatitis caused by the hepatitis C virus, which is transmitted through sexual contact or contact with infected blood or body fluids

Hepatitis D- a form of hepatitis that only causes symptoms when the individual is already infected with hepatitis B

Hepatoma- a cancerous tumor of the liver

Hepatomegaly- enlargement of the liver

Hereditary- describes a genetic trait that is passed from parents to children

Hereditary spherocytosis- a genetic disorder in which red blood cells are smaller, rounder, and more fragile than normal, causing hemolytic anemia

Hermaphroditism- a rare condition in which an individual is born with both male and female reproductive organs

Hernia- the bulging of an organ or tissue through a weakened area in the muscle wall

Herniated disk- see Disk prolapse

Herpes encephalitis- brain inflammation caused by a herpes simplex virus that has spread from another part of the body

Herpes simplex- infection by the herpes simplex virus, which causes blisterlike sores on the face, lips, mouth, or genitals; in rare cases, can also affect the eyes, fingers, or brain

Herpes zoster- see Shingles

Heterosexuality- being sexually attracted to members of the opposite sex

Hiatal hernia- a type of hernia in which the stomach bulges up into the chest cavity through an opening in the diaphragm

Hiccup- involuntary sudden contraction of the diaphragm along with the closing of the vocal cords, producing a "hiccup" sound

High-density lipoprotein- a type of protein found in the blood that removes cholesterol from tissues, protecting against heart disease

Hirschsprung's disease- a condition that is present at birth in which nerve cells do not develop in parts of the intestine, causing the intestine to narrow and block the passage of feces

Hirsutism- excessive hair or hair growth in unusual places, especially in women

Histamine- a chemical in some cells of the body that is released during allergic reactions, causing inflammation; also causes production of acid in the stomach and narrowing of the airways

H1 (histamine) blocker- a drug that blocks the action of histamine; used to treat inflammation

H2 (histamine) blocker- a drug used in the treatment of peptic ulcers that blocks histamine from causing acid production in the stomach

Histoplasmosis- a respiratory disease acquired by inhaling the spores of a fungus found in soil, especially where there are bird or bat droppings

Hives- the common term for urticaria, an itchy, inflamed rash that results from an allergic reaction

Hodgkin's disease- a cancer of lymphoid tissue (found in lymph nodes and the spleen) that causes the lymph nodes to enlarge and function improperly; may cause illness, fever, loss of appetite, and weight loss

Homeostasis- the body's coordinated maintenance of the stable, internal environment by regulating blood pressure, blood sugar, body temperature, etc

Homocystinuria- a genetic disorder in which an enzyme deficiency causes a substance called homocystine to build up in the blood, leading to mental handicap and skeletal abnormalities

Homosexuality- being sexually attracted to members of the same sex

Hookworm- infestation by a small, round, blood-sucking parasite; commonly causes a rash on the foot, but can also cause cough, pneumonia, and anemia

Hormonal implant- surgical insertion of a small object just under the skin that slowly releases a synthetic hormone for purposes such as birth control

Hormone- a chemical produced by a gland or tissue that is released into the bloodstream; controls body functions such as growth and sexual development

Hormone replacement therapy- the use of natural or artificial hormones to treat hormone deficiencies

Hospice- a hospital or an area of a hospital dedicated to treating people who are dying, often of a specific cause

Hot flash- a sudden, temporary feeling of heat and sometimes sweating; usually occurs as a result of low estrogen levels in women because of menopause or after a hysterectomy

HTLV- see Human T-cell lymphotrophic virus

Human immunodeficiency virus- a retrovirus that attacks helper T cells of the immune system and causes acquired immunodeficiency syndrome (AIDS); transmitted through sexual intercourse or contact with infected blood

Human T-cell lymphotrophic virus- a virus similar to HIV that affects the same helper T cells, but usually accompanies adult T-cell leukemia or T-cell lymphomas

Hydramnios- an excess of amniotic fluid in the uterus during pregnancy

Hydrocele- a painless swelling of the scrotum, caused by a collection of fluid around the testicle; commonly occurs in middle aged men

Hydrocephalus- excess cerebrospinal fluid within the brain; commonly referred to as "water on the brain"

Hydrocortisone- a corticosteroid drug that is used to treat inflammation and allergies

Hygiene- the practice, maintenance, and study of health; commonly refers to cleanliness

Hymen- a thin fold of membrane partly closing the opening of the vagina; usually torn during first sexual intercourse or insertion of a tampon

Hyperactivity- a type of behavior characterized by excessive physical activity, sometimes associated with neurological or psychological causes

Hyperalimentation- a method of providing nutrients by the use of a tube or intravenously to a person who cannot eat food or needs nutrients because of an illness

Hyperbilirubinemia- a condition in which there is too much bilirubin, a substance produced when red blood cells are broken down; can lead to jaundice

Hypercalcemia- a condition marked by abnormally high levels of calcium in the blood; can lead to disturbance of cell function in the nerves and muscles and, if not treated, can be fatal

Hypercholesterolemia- an abnormally high level of cholesterol in the blood, which can be the result of an inherited disorder or a diet that is high in fat

Hyperglycemia- a condition characterized by abnormally high levels of glucose in the blood, usually as a result of untreated or improperly controlled diabetes mellitus

Hyperlipidemia- a general term for a group of disorders in which lipid levels in the blood are abnormally high, including hypercholesterolemia

Hyperparathyroidism- overactivity of the parathyroid glands, which increases calcium levels in the blood (called hypercalcemia) and decreases calcium in bones (causing osteoporosis)

Hyperplasia- the enlargement of an organ or tissue

Hypersensitivity- an excessive response of the body’s immune system to a foreign protein

Hypertension- abnormally high blood pressure, even when at rest

Hyperthermia- an abnormally high body temperature

Hyperthyroidism- overactivity of the thyroid gland, causing nervousness, weight loss, fatigue, and diarrhea

Hypertrophy- increase in the size of an organ due to an increase in the size of its cells

Hyperventilation- abnormally rapid breathing

Hypochondriasis- an abnormal condition in which a person is overly concerned with health and believes that he or she is suffering from a major illness despite medical opinion to the contrary

Hypodermic needle- a thin, hollow needle attached to a syringe; used to inject a medication under the skin, into a vein, or into a muscle

Hypoglycemia- abnormally low levels of glucose in the blood

Hypoplasia- failure of a tissue or organ to develop normally

Hypotension- the medical term for abnormally low blood pressure, which results in reduced blood flow to the brain, causing dizziness and fainting

Hypothermia- an abnormally low body temperature

Hypothyroidism- underactivity of the thyroid gland, causing tiredness, cramps, a slowed heart rate, and possibly weight gain

Hypoventilation- a slower-than-normal breathing rate

Hypoxemia- a reduced level of oxygen in the blood

Hypoxia- a reduced level of oxygen in tissues

Hysterectomy- surgical removal of the uterus

Hysteria- a term used to describe symptoms that are caused by mental stress and occur in someone who does not have a mental disorder

Hysterosalpingography- an X-ray examination performed to examine the inside of the uterus and fallopian tubes, in order to investigate and possibly treat infertility

Hysteroscopy- a method used to examine the inside of the uterus and the cervix using a viewing instrument

I

Iatrogenic- a term used to describe a disease, disorder, or medical condition that is a direct result of medical treatment

Ichthyosis- a variety of diseases in which the skin is dry and scaly

Idiopathic- a term used to describe something that occurs of an unknown cause

Ileostomy- a surgical procedure in which the lower part of the small intestine (the ileum) is cut and brought to an opening in the abdominal wall, where feces can be passed out of the body

Ileum- the lowest section of the small intestine, which attaches to the large intestine

Ilium- one of the two bones that form the hip on either side of the body Imaging- the technique of creating pictures of structures inside of the body using X-rays, ultrasound waves, or magnetic fields

Immune deficiency- impairment of the immune system, which reduces protection against infection and illness

Immune system- the cells, substances, and structures in the body that protect against infection and illness

Immunity- resistance to a specific disease because of the responses of the immune system

Immunization- the process of causing immunity by injecting antibodies or provoking the body to make its own antibodies against a certain microorganism

Immunocompromised- weakening of the body’s immune system

Immunodeficiency- failure of the body’s immune system to fight disease

Immunoglobin- proteins in blood and tissue fluids that help destroy microorganisms such as bacteria and viruses

Immunology- the study of the immune system, including how it functions and disorders that affect it

Immunostimulant- a drug that increases the ability of the body’s immune system to fight disease

Immunosuppressant- a drug that inhibits the activity of the immune system; used to prevent rejection of a transplant organ and in disorders where the body's immune system attacks its own tissues

Impacted fracture- a bone break in which the two broken ends have been forced into each other

Imperforate anus- a birth defect in which the opening of the anus is not formed normally

Impetigo- a highly contagious skin infection caused by bacteria, usually occurring around the nose and mouth; commonly occurring in children

Implant- an organ, tissue, or device surgically inserted and left in the body

Impotence- the inability to acquire or maintain an erection of the penis

Incompetent cervix- an abnormally weak cervix, which widens prematurely during pregnancy as a result of the weight of a developing fetus; may result in a miscarriage

Incontinence- inability to hold urine or feces inside of the body

Incubation period- the time period between when an infectious organism enters the body and when symptoms occur

Indigestion- uncomfortable symptoms brought on by overeating or eating spicy, rich, or fatty foods; characterized by heartburn, pain in the abdomen, nausea, and gas, and can be more serious if recurrent

Induction of labor- the use of artificial means to start the process of childbirth

Infarction- tissue death due to lack of blood supply

Infection- disease-causing microorganisms that enter the body, multiply, and damage cells or release toxins

Infective arthritis- arthritis caused by bacteria from a wound or the bloodstream entering a joint

Infertility- the inability to have children as a result of sexual intercourse

Inflammation- redness, pain, and swelling in an injured or infected tissue produced as a result of the body's healing response

Inflammatory bowel disease- the general term for two inflammatory disorders affecting the intestines; also known as Crohn's disease and ulcerative colitis

Inflammatory joint disease- any type of arthritis that causes a joint to become inflamed

Influenza- a viral infection characterized by headaches, muscle aches, fever, weakness, and cough; commonly called the "flu"

Informed consent- agreement to undergo a medical procedure after the technique, its risks, and its possible complications have been explained

Infusion- the introduction of a substance, such as a drug or nutrient, into the bloodstream or a body cavity

Ingestion- taking something into the body through the mouth

Ingrown toenail- a painful condition of the big toe in which the nail grows into the skin on either side, causing inflammation and/or infection

Inguinal hernia- the bulging of a portion of the intestines or abdominal tissue into the muscles of the groin (the area just below the abdomen)

Inhaler- a device used to introduce a powdered or misted drug into the lungs through the mouth, usually to treat respiratory disorders such as asthma

Inheritance- the passing of traits from parent to child through genes

Injection- the use of a syringe and needle to insert a drug into a vein, muscle, or joint or under the skin

Insemination- the placement of semen into a woman's uterus, cervix, or vagina

In situ- "in place"; often describes a cancer that has not spread

Insomnia- difficulty falling or remaining asleep

Insulin- a hormone made in the pancreas that plays an important role in the absorption of glucose (the body's main source of energy) into muscle cells

Insulinoma- a noncancerous tumor of the insulin-producing cells of the pancreas; the tumor releases excess insulin into the blood, causing glucose levels to drop dangerously low

Intensive care- close monitoring of a patient who is seriously ill

Interferon- a protein produced by body cells that fights viral infections and certain cancers

Internal fixation- a method of holding a broken bone in place using surgically inserted screws, rods, or plates

Interstitial- lying between body structures or in the interspaces of tissues

Interstitial cystitis- persistent inflammation of the lining and muscle of the bladder

Interstitial lung disease- a disease of the connective tissue surrounding the air sacs of the lungs that causes a dry cough, scarring of lung tissue, and shortness of breath

Interstitial pulmonary fibrosis- scarring of connective tissue in the lungs that leads to shortness of breath

Interstitial radiation therapy- a treatment for cancer in which a radioactive material is inserted into or near a tumor to provide direct radiation

Intervertebral disks- broad, flat cartilage structures containing a gel-like fluid that cushion and separate vertebrae

Intestinal bypass- a surgical procedure in which the beginning of the large intestine is joined to its end so that less food is absorbed; because of serious side effects, usually performed only on seriously obese people

Intestine- a long, tube-shaped organ that extends from the stomach to the anus; absorbs food and water and passes the waste products of digestion as feces

Intra-aortic balloon pump- a small balloon inserted into the aorta that helps to circulate blood by inflating between heartbeats

Intractable- describes a condition that does not respond to treatment

Intramedullary rod- a strong metal rod that is placed inside of a broken bone to help it heal correctly

Intraocular pressure- the pressure of the fluids within the eye

Intrauterine device- a device inserted into the uterus that helps to prevent pregnancy

Intravenous- inside of or into a vein

Intrinsic- a term used to describe something originating from or located in a tissue or organ

Intubation- the passage of a tube into an organ or body structure; commonly used to refer to the passage of a tube down the windpipe for artificial respiration

Invasive- describes something that spreads throughout body tissues, such as a tumor or microorganism; also describes a medical procedure in which body tissues are penetrated

In vitro- "in glass"; a biological test or process that is carried out in a laboratory

In vitro fertilization- a treatment for infertility in which an egg and a sperm are joined outside the woman's body, and the fertilized egg is then inserted into the uterus or fallopian tube

In vivo- "in the living body"; a biological process that occurs inside of the body

Involuntary- occurring without a person’s control or participation

Iodine- an element for the formation of thyroid hormones

Ionizing radiation- radiation that damages cells or genes; can be used to treat cancer

IQ- intelligence quotient; a measure of a person's intelligence as determined by specific tests

Iris- the colored part of the eye

Iron- a mineral necessary for the formation of important biological substances such as hemoglobin, myoglobin, and certain enzymes

Iron-deficiency anemia- a type of anemia caused by a greater-than-normal loss of iron due to bleeding, problems absorbing iron, or a lack of iron in the diet

Irrigation- the cleansing of a wound by flushing it with water, a medicated solution, or some other fluid

Irritable bladder- involuntary contractions of muscles in the bladder, which can cause lack of control of urination

Irritable bowel syndrome- abnormal muscle movement in the intestines, which causes abdominal pain and irregular bowel movements (diarrhea, constipation, or both)

Ischemia- a condition in which a tissue or organ does not receive a sufficient supply of blood

IUD- see Intrauterine device

IVF- see In vitro fertilization

J

Jaundice- yellowing of the skin and whites of the eyes because of the presence of excess bilirubin in the blood; usually a sign of a disorder of the liver

Jock itch- an infection in the groin area caused by a fungus

Juvenile rheumatoid arthritis- a rare form of persistent joint inflammation that affects children

K

Kaposi's sarcoma- a skin cancer that is characterized by purple-red tumors that start at the feet and spread upward on the body; commonly occurs in people who have AIDS

Kawasaki disease- a childhood disease causing fever, rash, skin peeling, swollen lymph nodes, and possibly complications of the heart and brain

Keloid- a raised, firm, thick scar that forms as a result of a defect in the natural healing process

Keratin- a tough protein found in skin, nails, and hair

Keratitis- inflammation of the cornea

Keratolytic- drugs that remove the keratin-containing outer layer of skin; used to treat skin disorders such as warts and dandruff

Keratoplasty- surgical replacement or reshaping of the cornea

Keratosis- a growth on the skin that is the result of overproduction of the protein keratin

Ketoacidosis- the dangerous accumulation of chemicals called ketones in the blood, sometimes occurring as a complication of diabetes mellitus; also called ketosis

Kidney- one of two organs that are part of the urinary tract; responsible for filtering the blood and removing waste products and excess water as urine

Kidney stone- a hard mass composed of substances from the urine that form in the kidneys

Killer T cells- white blood cells that are part of the immune system and destroy microorganisms and cancer cells

Kilocalorie- a unit of energy; equal to a nutritional calorie

Kimmelstiel-Wilson syndrome- a kidney disorder that can occur as a complication of diabetes mellitus; can cause swelling, high blood pressure, and kidney failure

Klinefelter’s syndrome- a genetic disorder in which a man has at least 1 extra X chromosome in his cells, causing infertility and female characteristics

Knee-jerk reflex- a test for a reflexive extension of the leg to check the functioning of the nervous system; tapping the knee just below the kneecap should cause the lower part of the leg to jerk upward

Kyphosis- excessive curvature of the spine, which usually affects the top part of the spine and causes a hump

L

Labia- the two pairs of skinfolds that protect the opening of the vagina

Labor- the interval from onset of contractions to birth of a baby

Labyrinthitis- inflammation of the fluid-containing chamber of the inner ear (called the labyrinth) that maintains balance; can cause a feeling that one's surroundings are spinning around (known as vertigo)

Laceration- a torn or ragged wound

Lactase deficiency- an inherited disorder in which a person does not have the enzyme lactase, which breaks down lactose (the sugar found in dairy products); lactase deficiency leads to lactose intolerance, which means the inability to digest lactose

Lactation- the production of breast milk after giving birth

Lactation suppression- a decrease in milk production during pregnancy as a result of high levels of estrogen in the blood

Lactic acid- an acid produced by glucose-burning cells when these cells have an insufficient supply of oxygen

Lactose- the sugar found in dairy products

Lactose intolerance- inability to break down and absorb the sugar lactose

Lamaze method- a method of preparing for childbirth that stresses physical conditioning, relaxation, and breathing exercises

Laminectomy- a surgical procedure that removes part of a vertebra to relieve pressure on the spinal cord or a nerve branching from the spinal cord

Laparoscope- a viewing instrument used to examine and treat disorders in the abdominal cavity; consists of a long tube with an eyepiece, a lens, and often a camera, which allows the image to be viewed on a monitor

Laparoscopic cholecystectomy- surgical removal of the gallbladder using a laparoscope

Laparoscopy- a procedure done to examine the abdominal cavity using a laparoscope, usually to investigate pelvic pain or gynecologic conditions such as infertility

Large-cell carcinoma- one of the 4 major types of lung cancer

Large intestine- the part of the digestive tract that is located between the small intestine and the anus

Laryngectomy- surgical removal of all or part of the voice box (larynx) as a treatment for cancer

Laryngitis- inflammation of the voice box, usually caused by a viral infection; characterized by a hoarse voice

Larynx- the medical term for the voice box, the organ in the throat that produces voice and also prevents food from entering the airway

Laser treatment- the use of a laser (a concentrated beam of light) to perform medical procedures, such as the destruction of tumors

Latent infection- an infection that lies dormant in the body for months or years but can reappear

Lateral- on one side

Laxatives- drugs used to clear feces from the intestines; commonly used to treat constipation

Lazy eye- the common name for the visual defect resulting from untreated strabismus, in which the eyes are not correctly aligned

LDL- see Low-density lipoprotein

Lead poisoning- damage to the brain, nerves, red blood cells, or digestive system because of ingestion of lead

Learning disability- any of a variety of disorders, including hyperactivity, dyslexia, and hearing problems, that can interfere with a person's ability to learn

Legionnaires’ disease- a form of pneumonia that is mainly spread through air-conditioning systems and water

Leiomyoma- a noncancerous tumor of smooth muscle

Leishmaniasis- a group of parasitic diseases affecting the skin, mucous membranes, and internal organs; transmitted by the bite of a sandfly

Leptospirosis- infection by a spiral-shaped bacterium that affects the skin, eyes, muscles, kidneys, and liver; leptospirosis is carried by rodents

Lesch-Nyhan syndrome- a genetic disorder affecting only men that causes mental handicap, self-mutilation, and aggressive behavior

Lesion- an abnormality of structure or function in the body

Leukemia- a group of bone marrow cancers in which white blood cells divide uncontrollably, affecting the production of normal white blood cells, red blood cells, and platelets

Leukocyte- another name for a white blood cells

Leukocyte count- the number of white blood cells in the blood, which is used as a measure of health and possible infection

Leukodystrophy- a group of childhood genetic disorders in which the protective coverings of the nerves are destroyed

Leukoplakia- white patches that can develop in the mouth or on the penis or the opening of the vagina and are potentially cancerous

LH- see Luteinizing hormone

Lichen planus- a common skin disease in which itchy, small, pink or purple spots appear on the arms or legs

Ligament- a tough, elastic band of tissue that connects bones and suupports organs

Ligation- the process of closing a blood vessel or duct by tying it off

Lipid-lowering drugs- drugs taken to lower the levels of specific fats called lipids in the blood in order to reduce the risk of narrowing of the arteries

Lipidosis- any disorder in which fats cannot be properly broken down by the digestive system

Lipids- a group of fats stored in the body and used for energy

Lipoma- a noncancerous tumor of fatty tissue

Lipoproteins- substances containing lipids and proteins, comprising most fats in the blood

Liposarcoma- a cancerous tumor of fatty tissue

Liposuction- a surgical procedure in which fat is removed from areas of the body using a suction pump

Listeriosis- a rare bacterial infection acquired by eating undercooked infected meat or from infected live animals; can be dangerous to newborns and the elderly

Lithotripsy- a procedure done to break up stones in the urinary tract using ultrasonic shock waves, so that the fragments can be easily passed from the body

Liver- the largest organ in the body, producing many essential chemicals and regulating the levels of most vital substances in the blood

Liver failure- the final stage of liver disease, in which liver function becomes so impaired that other areas of the body are affected, most commonly the brain

Lobe- a well-defined, separate part of an organ

Lobectomy- surgical removal of a lobe

Local anesthesia- a method of preventing pain by inducing the loss of sensation in a certain area of the body while the patient remains awake

Locked joint- a joint that cannot be moved because of a disease or a lodged piece of bone or cartilage

Lockjaw- a spasm of the jaw muscles that prevents the mouth from opening, such as that caused by tetanus

Locomotor system- the structures of the body that are responsible for its movement

Lordosis- the inward curvature of the spine at the lower back, which is normal to a certain degree; abnormal as a result of certain medical conditions, being overweight, or having muscle problems

Lou Gehrig's disease- see Amyotrophic lateral sclerosis

Low-density lipoprotein- a type of lipoprotein that is the major carrier of cholesterol in the blood, with high levels associated with narrowing of the arteries and heart disease

Lumbago- dull, aching pain in the lower back

Lumbar puncture- a procedure in which a needle is inserted into the lower region of the spinal canal to take out a sample of spinal fluid or to inject a drug

Lumbar spine- the lower part of the spine between the lowest pair of ribs and the pelvis; made up of five vertebrae

Lumpectomy- surgical removal of a section of breast containing cancer Lung collapse- a condition in which all or part of a lung cannot expand and fill with air

Lungs- two organs in the chest that take in oxygen from the air and release carbon dioxide

Lupus erythematosus- a disorder of the immune system that causes inflammation of connective tissue

Luteinizing hormone- a hormone produced by the pituitary gland that causes the ovaries and testicles to release sex hormones and plays a role in the development of eggs and sperm

Lyme disease- a disease caused by bacteria transmitted through the bite of a tick; characterized by fever, rash, and inflammation of the heart and joints

Lymph- a milky fluid containing white blood cells, proteins, and fats; plays an important role in absorbing fats from the intestine and in the functioning of the immune system

Lymphadenopathy- swollen lymph nodes

Lymphangiography- an X-ray procedure that creates images of the lymphatic system

Lymphatic system- a network of vessels that drain lymph back into the blood

Lymph node- a small gland that is part of the immune system; contains white blood cells and antibodies and helps fight against the spread of infection

Lymphocyte- a white blood cell that is an important part of the body's immune system, helping to destroy invading microorganisms

Lymphocytic leukemia- a disease in which white blood cells called lymphocytes divide uncontrollably

Lymphogranuloma venereum- a sexually transmitted chlamydial infection; common in countries with a tropical climate

Lymphomas- a group of cancer of the lymph nodes and spleen that can spread to other parts of the body

Lymphosarcoma- another name for a non-Hodgkin's sarcoma; a cancerous tumor in lymphoid tissue

M

Macula- the area of the retina that allows fine details to be observed at the center of vision; also refers to any small, flat spot on the skin

Macular degeneration- gradual loss of vision due to deterioration of nerve tissue in the retina

Magnesium- a mineral that is essential for many body functions, including nerve impulse transmission, formation of bones and teeth, and muscle contraction

Magnetic resonance imaging (MRI)- a technique that uses magnetic fields and radio waves to create high-quality cross-sectional images of the body without using radiation

Malabsorption- an impaired ability of the lining of the small intestine to absorb nutrients from food

Malaria- a parasitic disease spread by mosquitos that causes chills and fever; potentially fatal complications in the liver, kidneys, blood, and brain are possible

Malformation- abnormal development of an organ or tissue

Malignant- a word used to describe a condition that is characterized by uncontrolled growth and/or that can be fatal, such as a cancerous tumor

Malignant hyperthermia- a reaction to certain anesthesia gases involving intense muscle contractions and a high fever

Malignant melanoma- the most serious type of skin cancer, in which a mole changes shape, darkens, becomes painful, and/or bleeds easily

Mallory-Weiss syndrome- a condition associated with alcoholism in which the lower end of the esophagus tears, causing vomiting of blood

Mammography- an X-ray procedure done to detect breast cancer

Mammoplasty- a general term for a cosmetic operation on the breasts; includes breast reduction, enlargement, and reconstruction after a mastectomy

Mandible- another term for the lower jaw

Mania- a mental disorder characterized by extreme excitement, happiness, overactivity, and agitation; usually refers to the high of the highs and lows experienced in manic-depressive disorder

Manic-depressive disorder- a mental disorder characterized by extreme mood swings, including either mania, depression, or a continuing shift between the two extremes

MAO inhibitor- see Monoamine oxidase inhibitor antidepressant

Marfan's syndrome- a rare genetic disorder that affects connective tissue, leading to abnormalities of joints, bones, tendons, ligaments, arteries, and/or the heart

Mast cell- a type of cell present in most body tissues that releases substances in response to an allergen, which causes symptoms such as inflammation

Mastectomy- a surgical procedure in which all or part of the breast is removed to prevent the spread of cancer

Mastitis- inflammation of the breast, which is usually caused by a bacterial infection

Maxilla- one of two bones that form the upper jaw, the roof of the mouth, and the center portion of the face

Measles- an illness caused by a viral infection, causing a characteristic rash and a fever; primarily affects children

Meconium- thick, sticky, greenish-brown stool passed by a postmature fetus, or one experiencing fetal distress, into the amniotic fluid, or by an infant during the first couple of days after birth

Medial- a term used to describe something situated on or near the midline of the body or a body structure

Median nerve- a nerve running down the arm to the hand; controls muscle movement in the forearm and hand and conveys sensation from part of the hand

Mediastinoscopy- investigation of the central chest compartment using an endoscope that is inserted through an incision in the neck

Medulla- the center part of an organ or body structure; sometimes used to refer to the lower part of the brain stem

Medulloblastoma- a type of cancerous tumor, occurring in the section of the brain that controls posture and balance; found mainly in children

Megacolon- a severely swollen large intestine, causing severe constipation and abdominal bloating; may be present at birth or develops later

Megaloblastic anemia- a type of anemia in which a lack of the vitamin B12 or folic acid interferes with red blood cells and causes them to be enlarged and deformed, resulting in tiredness and weight loss

Meiosis- the type of cell division that occurs only in the ovaries and testicles, producing cells with half the genes of the original cell; these cells then form eggs and sperm

Melanin- the pigment that gives skin, hair, and eyes their coloring

Melanocytes- cells that produce the pigment melanin

Melanocyte-stimulating hormone- a hormone that coordinates pigmentation of the skin, eyes, and hair

Melanoma- a skin tumor composed of cells called melanocytes

Menarche- the beginning of menstruation

Meniere's disease- a disorder of the inner ear, causing hearing loss, ringing in the ear, and the sensation that one's surroundings are spinning

Meninges- the three membranes that surround and protect the spinal cord and brain

Meningioma- a rare noncancerous tumor developing in the protective membranes covering the brain called the meninges; can cause headaches and problems with vision and mental function

Meningitis- inflammation of the meninges; usually caused by infection by a microorganism (meningitis caused by bacteria is life-threatening; viral meningitis is milder)

Meningocele- a protrusion of the meninges through an opening in the skull or spinal cord due to a genetic defect

Meniscectomy- surgical removal of all or part of a cartilage disk from a joint

Meniscus- a crescent-shaped pad of cartilage in joints that helps to reduce friction

Menopause- the period in a woman's life when menstruation stops, resulting in a reduced production of estrogen and cessation of egg production

Menorrhagia- excessive loss of blood during menstruation, which can be caused by disorders of the uterus

Menstrual cycle- the periodic discharge of blood and mucosal tissue from the uterus, occurring from puberty to menopause in a woman who is not pregnant

Menstruation- the shedding of the lining of the uterus during the menstrual cycle Mesenteric infarction- death of tissue in the intestine due to lack of blood supply to that tissue

Mesenteric lymphadenitis- inflammation of lymph nodes in an abdominal membrane

Mesothelioma- a cancerous tumor occurring in the lining of the lungs and chest cavity, often associated with exposure to asbestos dust

Mesothelium- a tissue layer that lines the heart, abdomen, chest cavity, and lungs

Messenger RNA- an RNA molecule that transports the information stored in DNA out of a cell's nucleus in order to make proteins

Metabolic rate- the speed at which the body uses energy

Metabolism- a general term for all of the chemical processes that occur in the body

Metabolite- any substance that takes part in a chemical reaction in the body

Metastasis- the spreading of a cancerous tumor to another part of the body through lymph, blood, or across a cavity; also sometimes refers to a tumor that has been produced in this way

Metered-dose inhaler- an inhaler that gives a specific amount of medication with each use

Microbe- another term for a microorganism, especially one that causes disease Microbiology- the study of microorganisms

Microcephaly- an abnormally small head

Microdiskectomy- surgical removal of the protruding part of a prolapsed disk

Microorganism- any tiny, single-celled organism (such as a bacterium, virus, or fungus)

Microsurgery- a surgical technique that uses a special binocular microscope to operate on tiny, delicate, or hard-to-reach tissues

Micturition syncope- fainting or feeling weak while standing at the toilet; caused by an abnormal heartbeat or a drop in blood pressure

Middle ear- the small cavity between the eardrum and inner ear; contains three tiny, linked bones that transmit sound to the inner ear

Middle ear effusion- the buildup of fluid in the middle ear, which can affect hearing

Midwifery- a profession concerned with providing care to a mother and baby during pregnancy and childbirth

Migraine- a severe headache, usually accompanied by vision problems and/or nausea and vomiting, and that typically recurs

Mineral- a substance that is a necessary part of a healthy diet (such as potassium, calcium, sodium, phosphorus, and magnesium)

Minipill- an oral contraceptive containing only the synthetic hormone progesterone (birth control pills contain estrogen and progesterone)

Miotic- a drug that causes the pupil to constrict

Miscarriage- expulsion of a fetus before it has developed sufficiently to survive on its own

Mites- small eight-legged animals, many of which burrow and feed on blood

Mitosis- the process by which most cells divide in order to reproduce

Mitral insufficiency- a problem with the ability of the mitral valve in the heart to close, which causes the heart to pump harder and reduces its efficiency

Mitral stenosis- a condition in which the mitral valve in the heart becomes narrowed, making the heart work harder to pump blood; can lead to symptoms such as shortness of breath

Mitral valve- the valve in the heart that allows blood to flow from the left atrium to the left ventricle, but prevents blood from flowing back in

Mitral valve prolapse- a common condition in which the mitral valve in the heart is deformed, causing blood to leak back across the valve; characterized by a heart murmur and sometimes chest pain and disturbed heart rhythm

Modified radical mastectomy- a treatment for breast cancer in which the entire breast, a section of the chest muscle, and lymph nodes in the chest and underarm are removed

Molar tooth- large, strong teeth at the back of the jaw, primarily used to grind food

Mole- a brown to dark-brown spot on the skin that can be flat or raised

Molecule- the smallest unit of a substance that possesses its characteristics

Molluscum contagiosum- a viral infection that causes white bumps on the skin; usually clears up in a few months

Mongolian spot- a brown to blue-black spot on the lower back and buttocks at birth, caused by a concentration of pigment-producing cells; usually disappears by the age of 3 or 4 years

Monoamine oxidase inhibitor antidepressant- a substance that works by stopping an enzyme that breaks down stimulating chemicals in the brain; used to treat depression

Monoclonal antibodies- an antibody that is produced in the laboratory so that it will react with only one specific foreign protein; used to help diagnose certain kinds of cancer

Mononucleosis- an infection caused by a virus that invades a type of white blood cell called a monocyte, causing fever, sore throat, and swollen lymph nodes

Monounsaturated fat- a type of fat that is thought to be beneficial in the prevention of coronary heart disease; found in foods such as olive oil and peanut oil

Morbidity- the state of being ill or having a disease

Morning sickness- nausea and vomiting experienced early in a pregnancy, affecting about half of all pregnant women

Mortality- the death rate, measured as the number of deaths per a certain population; may describe the population as a whole, or a specific group within a population (such as infant mortality)

Motor nerve- a nerve that carries messages to a muscle that cause the muscle to contract

Motor neuron disease- degeneration of the nerves in the spinal cord and brain that are responsible for muscle movement, causing weakness and muscle deterioration

Mouth-to-mouth resuscitation- a method of artificial breathing in which someone rhythmically forces air into the lungs of a person who has stopped breathing

MRI- see Magnetic resonance imaging

MS- see Multiple sclerosis

Mucocele- a sac or body cavity that is swollen because of the production of mucus by the cells in its lining

Mucolytic- a drug that lessens the sticky quality of phlegm and makes it easier to cough up

Mucous membrane- the soft, pink layer of cells that produce mucus in order to keep body structures lubricated; found in structures such as the eyelids, respiratory tract, and urinary tract

Mucus- a slippery fluid produced by mucous membranes that lubricates and protects the internal surfaces of the body

Multi-infarct dementia- dementia caused by multiple strokes

Multiple-gated acquisition scan- a technique for evaluating heart efficiency by measuring blood flow into and out of the heart

Multiple myeloma- a cancer that causes uncontrolled production of white blood cells in the bone marrow

Multiple pregnancy- the presence of more than one fetus in the uterus, such as occurs with twins

Multiple sclerosis- a disease in which the protective coverings (myelin) of nerve fibers in the brain are gradually destroyed; symptoms vary from numbness to paralysis and loss of control of bodily function

Mumps- a viral infection that causes inflammation of salivary glands; primarily affects children

Murmur- a characteristic sound (heard through a stethoscope) of blood flowing irregularly through the heart; can be harmless or may be an indication of disease

Muscle fibers- specialized, contracting cells that are bundled together to form muscles

Muscle relaxants- a group of drugs used to relieve muscle spasm and to treat conditions such as arthritis, back pain, and nervous system disorders such as stroke and cerebral palsy

Muscle tone- the natural tension in resting muscles

Muscle wasting- the degeneration of a muscle (loss of bulk), caused by disease or starvation

Muscular dystrophy- a rare genetic disorder in which muscles degenerate gradually and strength is lost

Mutagen- anything that can increase the rate of abnormal change in cells, which can lead to cancer

Mutation- a change in the genetic information within a cell

Myalgia- the medical term for muscle pain

Myasthenia gravis- a disease in which the muscles, mainly those in the face, eyes, throat, and limbs, become weak and tire quickly; caused by the body's immune system attacking the receptors in the muscles that pick up nerve impulses

Mycobacterium- a type of slow-growing bacterium; resistant to the body's defense mechanisms and are responsible for diseases such as tuberculosis and leprosy

Mycoplasma- the smallest free-living microorganisms

Mycosis- any disease caused by a fungus

Mydriatic- a drug that causes the pupil to dilate (widen)

Myelin sheath- the fat- and protein-containing material that surrounds and protects some nerves

Myelitis- inflammation of the spinal cord, which can cause headaches, fever, muscle stiffness, pain, weakness, and eventually paralysis

Myelocele- protrusion of the spinal cord and its coverings out from the spine; one of the more severe forms of spina bifida

Myeloma- a cancer affecting cells in the bone marrow; sometimes used as an abbreviation for multiple myeloma

Myelosclerosis- buildup of fibrous connective tissue in the bone marrow, affecting the production of blood components

Myocardial infarction- the death of an area of heart muscle as a result of being deprived of its blood supply; characterized by severe pain in the chest; commonly called a heart attack

Myocarditis- inflammation of the heart muscle, which can be caused by a virus, certain drugs, or radiation therapy

Myocardium- the medical term for heart muscle

Myomectomy- the surgical removal of a noncancerous tumor from muscle

Myopathy- a muscle disease, usually one that results in the deterioration of muscle

Myopia- the medical term for nearsightedness

Myositis- muscle inflammation, causing pain and weakness

Myringotomy- a surgical opening in the eardrum that allows for drainage

Myxoma- a noncancerous tumor made of mucous material and fibrous connective tissue

N

Narcolepsy- a disorder that causes excessive sleepiness during the day and frequent and uncontrollable episodes of falling asleep

Narcosis- a drug (or other chemical)-induced drowsiness or stupor

Narcotic- an addictive substance that blunts the senses; can cause confusion, stupor, coma, and death with increased dosages

Narcotic analgesics- a type of painkiller that blocks the transmission of pain signals in the brain; often cause tolerance (the need for higher amounts of the drug to produce the same effect) and drug dependence

Nasal septum- the section of the nose that divides the left and right nostrils; made of cartilage and bone and covered by a mucous membrane

Nasogastric tube- a thin, plastic tube that is inserted through the nose, down the esophagus, and into the stomach; used to drain, wash, or take samples from the stomach, or to feed very sick patients who cannot eat

Nasopharynx- the passageway connecting the back of the nose to the top of the throat

Natural childbirth- a technique of giving birth that stresses relaxation techniques so that the use of pain-relieving drugs can be minimized; also called prepared childbirth

Natural methods of family planning- methods of planning a family that focus on a woman's time of ovulation, either so that pregnancy can be avoided or conception is likely

Nausea- feeling the need to vomit

Nebulizer- an instrument that provides a drug in its misted form through a face mask; used for severe asthma attacks and for children who have asthma but cannot use an inhaler

Necrosis- the medical term for the death of tissue cells

Needle aspiration- the use of a thin, hollow needle and syringe to remove body fluid for examination

Needle biopsy- the use of a hollow, wide-diameter needle to remove a sample of tissue for examination

Neonate- a term used to describe a newborn infant from birth to 1 month of age

Neoplasm- another term for a tumor

Nephrectomy- the surgical removal of one or both kidneys

Nephritis- inflammation of one or both kidneys because of an infection, an abnormal immune system response, or a disorder of metabolism

Nephroblastoma- a fast-growing cancer of the kidneys that occurs most commonly in children under 4 years of age

Nephrolithotomy- surgical removal of a kidney stone

Nephrons- the tiny filtering units of the kidney

Nephrosclerosis- the replacement of normal kidney structures with scar tissue

Nephrostomy- the surgical placement of a tube into the kidney to drain urine

Nephrotic syndrome- symptoms that result from damage to the filtering units of the kidney

Nerve- a bundle of fibers that transmit electrical messages between the brain and areas of the body; these messages convey sensory or motor function information

Nerve block- the dulling of sensation in an area of the body by injecting a painkiller into or around a nerve leading to that section of the body

Nerve cell- the basic unit of the nervous system; transmits chemical messages throughout the body

Nerve compression- pressure on a nerve, which can cause nerve damage and muscle weakness

Neuralgia- pain along the course of a nerve caused by irritation or damage to the nerve

Neural tube- the tube located along the back of an embryo that later develops into the spinal cord and brain

Neural tube defects- problems in the development of the spinal cord and brain in an embryo, such as the failure of the spine to enclose the spinal cord (spina bifida) and the failure of the brain to develop (anencephaly)

Neuritis- inflammation of a nerve, often characterized by pain, numbness, or tingling; also used to describe nerve damage and disease from causes other than inflammation

Neuroblastoma- a cancerous childhood tumor located in the adrenal glands or the sympathetic nervous system

Neurofibrillary tangles- abnormal spiral filaments on nerve cells in the brain; characteristic of Alzheimer disease

Neurofibromatosis- a condition in which connective tissue tumors occur on nerves in the skin

Neuroleptic- an antipsychotic drug

Neuroma- a noncancerous tumor occurring in nerve tissue

Neuron- another term for a nerve cell

Neuropathy- disease, inflammation, or damage to the nerves connecting the brain and spinal cord to the rest of the body

Neurosis- relatively mild emotional disorders (such as mild depression and phobias)

Neurotoxins- chemicals that attack and damage nerve cells

Neurotransmitters- chemicals that transfer messages from one nerve cell to another or from a nerve cell to a muscle cell

Neutrophil- a type of white blood cell

Nevus- a marking on the skin; can be present at birth (birthmark) or develop later (such as a mole)

Newborn respiratory distress syndrome- a disorder in which premature babies lack surfactant, a substance that stops the lungs from collapsing

Niacin- a vitamin important in many chemical processes in the body; also known as vitamin B3

Night terrors- a form of nightmlare causing abrupt awakening in terror; occurs mostly in children

Nitrates- a group of drugs that widen blood vessels; used to treat insufficient blood supply to the heart (angina pectoris) and reduced pumping efficiency of the heart (heart failure)

Nocturia- urination or a sleep-disturbing need to urinate during the night

Nocturnal emission- ejaculation of semen during sleep, which is normal in adolescent males; commonly called a wet dream

Node- a small, rounded tissue mass

Nodule- a small lump of tissue that is usually abnormal; can form under the skin or protrude

Nondisjunction- an error that occurs during the division of sex chromosomes, causing either too much or too little genetic information to be placed in an egg or sperm when it is formed

Non-Hodgkin's lymphoma- any cancer in lymphoid tissue (found mostly in the spleen and lymph glands) that is not Hodgkin's disease

Non-insulin-dependent diabetes- a type of diabetes mellitus that occurs mainly in those over 40 who are overweight; it is usually treated with diet changes and drugs that increase production of insulin by the pancreas (also known as type II diabetes mellitus)

Noninvasive- a term that is used to describe medical procedures that do not enter or penetrate the body; also refers to noncancerous tumors that do not spread to other sections of the body

Nonnarcotic analgesic- a drug that relieves pain by blocking the production of chemicals that stimulate pain-sensing nerves

Nonsteroidal anti-inflammatory drugs- a group of drugs that relieve pain and reduce inflammation

Norepinephrine- a hormone that regulates blood pressure by causing blood vessels to narrow and the heart to beat faster when blood pressure drops

Norwalk virus- a virus that causes acute gastroenteritis

Nosocomial infection- an infection acquired in a hospital

NSAID- see Nonsteroidal anti-inflammatory drug

Nucleic acids- substances found in every living organism that provide the instructions for development; includes DNA and RNA

Nucleotide bases- molecules that form nucleic acids

Nucleus- the center or most important point of an object

Numbness- the lack of sensation in a part of the body because of interruption of nerve impulses

Nurse-midwife- a registered nurse who specializes in the care of a mother and child during pregnancy, labor, and delivery

Nutrient- any substance that the body can use to maintain its health Nystagmus- persistent, rapid, involuntary movement of the eyes

O

Oat cell carcinoma- another term for small-cell carcinoma

Obesity- a condition in which there is an excess of body fat; used to describe those who weigh at least 20 percent more than the maximum amount considered normal for their age, sex, and height

Obsessive-compulsive disorder- a mental disorder in which a person is obsessed with certain thoughts, leading them to repeatedly perform specific acts; for example, constantly washing the hands out of fear of germs and dirt

Obstructive sleep apnea- the blockage of the airways during sleep, which causes breathing to stop for very short periods of time, commonly caused by excessive relaxation of muscles at the back of the throat

Occlusion- the blocking of an opening or passageway in the body

Occult blood- blood in the feces that can be detected only by chemical tests

Occupational disease- a disease that occurs as a result of factors in the workplace

Occupational therapy- treatment to relearn physical skills lost as a result of an illness or accident

Ocular- describes something related to the eyes

Oculomotor nerves- nerves that stimulate movement of the eyeball

Olfactory nerves- nerves that play a role in the sense of smell

Oligodendroglioma- a rare type of cancerous brain tumor that occurs most commonly in the cerebrum

Oligohydramnios- an unusually small amount of amniotic fluid surrounding the fetus in the uterus, which can lead to complications with the pregnancy

Oligospermia- a low level of sperm in the semen; one of the main causes of infertility in men

Oncogenes- genes that, when altered by environmental factors or viruses, can cause abnormal cell growth

Oocyte- an egg cell that has not developed completely

Oophorectomy- the surgical removal of one or both ovaries; used to treat the growth of ovarian cysts or tumors

Open heart surgery- any operation in which the heart is stopped temporarily and a machine is used to take over its function of pumping blood throughout the body

Ophthalmia- severe inflammation of the eyes

Ophthalmoplegia- partial or total loss of the ability to move the eyes

Ophthalmoscopy- examination of the inside of the eye using a lighted viewing instrument

Opportunistic infection- infection by organisms that would be harmless to a healthy person, but cause infection in those with a weakened immune system (for example, persons with AIDS or chemotherapy patients)

Optic- pertaining to the eyes

Optician- a person who specializes in the making and adjustment of eyeglasses and contact lenses

Optic nerves- the pair of nerves that carry visual information from the retina to the brain

Optic neuritis- inflammation of the optic nerve, often causing a partial loss of vision

Oral contraceptives- drugs taken in pill form to prevent pregnancy; contain synthetic progesterone and estrogen hormones

Orbit- the socket in the skull that contains the eyeball, along with its blood vessels, nerves, and muscles

Orchiectomy- the surgical removal of one or both of the testicles

Orchiopexy- an operation to correct an undescended testicle

Orchitis- inflammation of a testicle, which can be caused by infection with the mumps virus

Organ donation- an agreement to allow one or more organs to be removed and transplanted into someone else

Organism- any single, functioning form of life

Orgasm- involuntary contraction of genital muscles experienced at the peak of sexual excitement

Orphan drugs- drugs used to treat rare diseases; not normally produced because potential sales are small

Orthopnea- breathing difficulty experienced while lying flat; can be a symptom of heart failure or asthma

Orthotic- a device used to correct or control deformed bones, muscles, or joints

Osgood-Schlatter disease- painful enlargement and inflammation of the area of the shinbone just below the knee, usually occurring in adolescent boys

Osmosis- the process of passage of the solvent portion of a lesser-concentrated solution through a semipermeable membrane into a higher-concentrated solution until the two solutions are equal in concentration; plays an important role in water distribution in the body

Ossification- the formation and maintenance of bone

Osteitis- inflammation of bone

Osteitis deformans- another name for Paget's disease

Osteoarthritis- see Degenerative arthritis

Osteoblast- a cell that forms bone

Osteochondritis dissecans- bone degeneration inside of a joint, causing small pieces of bone and cartilage to become detached

Osteochondritis juvenilis- inflammation of a growing section of bone in a child or adolescent

Osteochondroma- a noncancerous tumor made up of bone and cartilage

Osteoclast- a cell that breaks down unwanted bone tissue; also refers to a device for fracturing a bone to correct a deformity

Osteodystrophy- defective bone formation

Osteogenesis imperfecta- a genetic disorder in which bones are abnormally fragile, leading to multiple breaks and deformity

Osteolysis- the softening and destruction of bone

Osteoma- a noncancerous bone tumor

Osteomalacia- the loss of minerals and softening of bones because of a lack of vitamin D; called rickets in children

Osteomyelitis- the inflammation of bones and bone marrow because of an infection, usually caused by bacteria

Osteopetrosis- a rare hereditary disorder in which bones become harder and more dense, causing them to break more easily

Osteophyte- an outgrowth of bone near a joint

Osteoporosis- a condition in which bones become less dense, more brittle, and fracture easily

Osteosarcoma- a cancerous bone tumor

Osteosclerosis- an abnormal increase in density and hardness of bone

Otalgia- the medical term for an earache

OTC remedy- see Over-the-counter remedy

Otitis externa- inflammation of the outer ear due to an infection; commonly called swimmer's ear

Otitis media- inflammation of the middle ear (between the eardrum and inner ear) because of the spread of an infection from the nose, sinuses, and throat

Otorrhea- a discharge from an inflamed ear

Otosclerosis- progressive deafness caused by bone formation around structures in the middle ear

Ototoxicity- harmful effect that some drugs have on the organs or nerves in the ears, which can lead to hearing and balance problems

Outpatient treatment- medical attention that does not include an overnight stay at a hospital

Ovaries- two almond-shaped glands located at the opening of the fallopian tubes on both sides of the uterus; produce eggs and the sex hormones estrogen and progesterone

Overdose- an excessively large dose of a drug, which can lead to coma and death

Over-the-counter remedy- a medication that can be purchased without a physician's prescription

Ovulation- the development and release of the egg from the ovary, which usually occurs halfway through a woman's menstrual cycle

Ovum- another term for an egg cell

Oxidation- a chemical reaction involving active sources of oxygen (called oxygen free radicals) that damages cells

Oximetry- determination of the amount of oxygen in the blood by measuring the amount of light transmitted through an area of skin

Oxygen- a gas that is colorless, odorless, and tasteless; essential to almost all forms of life

Oxygen free radicals- active forms of oxygen found in pollution, cigarette smoke, and radiation that can damage cells and are believed to play a role in the aging process and cancer

Oxytocin- a hormone produced in the pituitary gland that causes contraction of the uterus during childbirth and stimulation of milk flow during breast-feeding

Ozone- a poisonous form of oxygen that is present in the earth's upper atmosphere, where it helps to screen the earth from damaging ultraviolet rays

P

Pacemaker- a small electronic device that is surgically implanted to stimulate the heart muscle to provide a normal heartbeat

Paget's disease- a disorder occurring in the middle-aged and elderly in which bone does not form properly, causing bone weakening, thickening, and deformity

Palate- the roof of the mouth

Palliative treatment- treatment that relieves the symptoms of a disorder without curing it

Pallor- abnormally pale skin; usually refers to the skin of the face

Palpation- the use of the hands to feel parts of the body to check for any abnormalities

Palpitation- an abnormally rapid and strong heartbeat

Palsy- loss of sensation or ability to move

Pancreas- a long gland located behind the stomach that produces enzymes that help to break down food and hormones (insulin and glucagon) that help to regulate glucose levels in the blood

Pancreatitis- inflammation of the pancreas, which is often caused by alcohol abuse

Pandemic- a widespread epidemic

Panic disorder- an emotional disorder characterized by attacks of anxiety that have no normal causes; usually made worse by stress

Papilloma- a tumor occurring on the skin or mucous membranes; usually not cancerous

Pap smear- a test in which cells are scraped off the cervix and examined for abnormalities; used to detect changes that might precede cervical cancer and to diagnose viral infections such as herpes simplex

Paracentesis- the insertion of a needle into a body cavity to relieve pressure, inject a drug, or remove a sample for analysis

Paralysis- the inability to use a muscle because of injury to or disease of the nerves leading to the muscle

Paramedic- a person trained to give first aid and other emergency medical care

Paranoia- a disorder in which a person becomes overly suspicious and emotionally sensitive

Paraphimosis- strangulation of the head of the penis by a tight or inflamed foreskin that has been pulled back

Paraplegia- complete or partial loss of sensation and movement of the legs

Parasite- an organisms that lives on or in other organisms, from which it obtains nutrients

Parasympathetic nervous system- the part of the autonomic nervous system that is stimulated during times of relaxation

Parathyroidectomy- the surgical removal of one or more of the parathyroid glands

Parathyroid glands- small glands located in the neck that produce a hormone that regulates the levels of calcium in the blood

Parathyroid hormone- a hormone released by the parathyroid glands that plays a role in controlling calcium levels in the blood

Parenteral- the introduction of a substance into the body by any route other than the digestive tract, such as through a vein or muscle

Paresis- partial paralysis

Paresthesia- numbness or tingling in the skin; commonly referred to as "pins and needles"

Parkinson's disease- a brain disorder in which there is a lack of the chemical messenger dopamine, which helps control muscle movement; leads to muscle stiffness, weakness, and trembling

Paronychia- a bacterial or yeast infection of the skin around the nail

Parotid glands- salivary glands located in the mouth near the ears

Paroxysm- a sudden attack or worsening of a disease's symptoms

Partial mastectomy- a treatment for breast cancer in which a tumor is removed, along with the skin covering it and some of the surrounding tissues and muscles

Partial seizure- an abnormal electrical discharge in a certain area of the brain, affecting only certain functions

Passive exercise- exercise of an injured part of the body involving no effort from that injured part

Passive smoking- a nonsmoker inhaling the cigar, cigarette, or pipe smoke of others (called second-hand smoke) in the same area, which increases the nonsmoker's risk of cancer and respiratory disorders

Patella- the medical term for the kneecap

Patent- not obstructed; open

Patent ductus arteriosus- a genetic disorder of the heart in which a channel connecting the pulmonary artery and the aorta fails to close and the heart must work harder to supply the body with blood

Paternity testing- use of blood tests to match up DNA or specific blood proteins to determine whether a man is the father of a child

Pathogen- any substance capable of causing a disease; usually refers to a disease-causing microorganism

Pathogenesis- the production and development of a disease or disorder

Pathology- the study of disease

Patient-controlled analgesia- a system for administering pain-killing drugs in which the amount of drug delivered is controlled by the patient

Peak flow measurement- the maximum speed that air is exhaled from the lungs; used to diagnose asthma or to determine the effectiveness of asthma medications

Pectoral muscles- the muscles of the upper part of the chest that move the arm across the body, raise some of the ribs, and move the shoulders

Pellagra- a deficiency of the vitamin niacin; causes dermatitis, diarrhea, and mental disorders

Pelvic examination- an examination of a woman's reproductive organs

Pelvic inflammatory disease- inflammation of a woman's internal reproductive organs, usually as a result of a bacterial infection; one of the most common causes of pelvic pain and infertility in women

Pelvis- the group of bones in the lower part of the trunk that support the upper body and protect the abdominal organs

Penile function tests- tests used to determine the cause of impotence, including blood tests and nerve function tests

Penile implant- an inflatable device surgically inserted into the penis that allows a man with impotence to have sexual intercourse

Penis- the external male reproductive organ, which passes urine and semen out of the body

Pepsin- the enzyme found in gastric juice that helps digest protein

Peptic ulcer- an erosion in the lining of the esophagus, stomach, or small intestine, usually caused in part by the corrosive action of gastric acid

Percutaneous- a procedure that is performed through the skin, such as an injection

Perforation- a hole in an organ or body structure caused by disease or injury

Periarteritis nodosa- inflammation and weakening of small and medium arteries

Pericardial effusion- fluid buildup inside of the pericardium, affecting the performance of the heart

Pericarditis- inflammation of the membranous sac that covers the heart, causing chest pain and fever

Pericardium- the membranous sac that covers the heart and the base of the blood vessels that are attached to the heart

Perinatal- occurring just before or just after birth

Periosteum- the tissue covering bones, except the surfaces in joints

Periostitis- inflammation of the periosteum

Peripheral nervous system- the nerves that branch out from the brain and spinal cord to the rest of the body

Peripheral vascular disease- the narrowing of blood vessels in the legs or arms, causing pain and possibly tissue death (gangrene) as a result of a reduced flow of blood to areas supplied by the narrowed vessels

Peristalsis- wavelike movement of smooth muscle-containing tubes, such as the digestive tract

Peritoneum- the membrane that lines the abdominal cavity and covers the abdominal organs

Peritonitis- inflammation of the peritoneum

Pernicious anemia- an anemia caused by a failure to absorb vitamin B12; which is essential in the production of normal red blood cells

Perthes' disease- inflammation of the growing head of a femur; a type of osteochondritis juvenilis

Pertussis- a bacterial infection of the respiratory tract characterized by short, convulsive coughs that end in a whoop sound when breath is inhaled (commonly called whooping cough); mainly affects children

Petit mal- a seizure characterized by loss of awareness for brief periods

PET scanning- see Positron emission tomography scanning

Peutz-Jeghers syndrome- a genetic disorder in which there are polyps in the small intestine and brown melanin spots on the lips, mouth, fingers, and toes

pH- a measure of the acidic or basic character of a substance

Phagocyte- an immune system cell that can surround and digest foreign bodies, unwanted cellular material, and microorganisms

Phantom limb- the sensation of a limb after it has been amputated

Pharmacology- the study of medications, including drug development

Pharyngitis- inflammation of the throat (the pharynx), causing sore throat, fever, earache, and swollen glands

Pharynx- the throat; the tube connecting the back of the mouth and nose to the esophagus and windpipe

Phenothiazines- a group of drugs used as antipsychotics, antihistamines, and antiemetics

Phenylketonuria- a hereditary disorder in which the enzyme that converts the amino acid phenylalanine into another amino acid is defective, meaning phenylalanine must be kept out of the diet

Pheochromocytoma- a noncancerous tumor of cells that produce epinephrine and norepinephrine, causing higher levels of these hormones in the blood and an increase in blood pressure

Phimosis- tightness of the foreskin, which prevents it from being moved back over the head of the penis

Phlebitis- inflammation of a vein

Phlebothrombosis- formation of a blood clot in a vein

Phlegm- mucus and other material produced by the lining of the respiratory tract; also called sputum

Phobia- a persisting fear of and desire to avoid something

Phosphates- salts containing phosphorus; essential to some body functions such as the bones and teeth

Phospholipids- fatty substances that make up the membranes surrounding cells

Phosphorus- a mineral that is an important part of structures such as bones, teeth, and membranes in the body; also involved in numerous other chemical reactions

Photocoagulation- tissue destruction using a focused beam of light

Photophobia- an abnormal sensitivity of the eyes to light

Photosensitivity- an abnormal reaction to sunlight, which usually occurs as a rash

Phototherapy- treatment with some form of light

Physical therapy- the treatment of injuries or disorders using physical methods, such as exercise, massage, or the application of heat

Physiology- the study of the body’s functions

Phytochemicals- chemicals in plants that might help protect against disorders such as cancer

Pica- a desire to eat materials that are not food

Pickwickian syndrome- extreme obesity along with shallow breathing, sleep apnea, excessive sleepiness, and heart failure

PID- see Pelvic inflammatory disease

Pigmentation- the coloration of the skin, hair, and eyes by the pigment melanin

Pinkeye- inflammation of the membrane that covers the white of the eyes and lines the eyelids, causing redness, discomfort, and a discharge; can be caused by infection or allergies

Pinworm- a small parasite worm that can live in the intestines; commonly affects children

Pituitary adenoma- a noncancerous tumor of the pituitary gland

Pituitary gland- a small, round gland located at the base of the brain that releases hormones that control other glands and body processes

Pityriasis alba- a common childhood or adolescent disorder in which there are pale, scaly patches on the skin of the face

Pityriasis rosea- a mild skin condition in which flat, scaly spots occur on the trunk and upper arms

Pivot joint- a joint designed for rotational movement PKU- see Phenylketonuria

Placebo- a chemically inactive substance given in place of a drug to test how much of a drug's effectiveness can be attributed to a patient's expectations that the drug will have a positive effect

Placebo effect- the positive or negative response to a drug that is caused by a person's expectations of a drug rather than the drug itself

Placenta- an organ formed in the uterus during pregnancy that links the blood of the mother to the blood of the fetus; provides the fetus with nutrients and removes waste

Placental abruption- the separation of the placenta from the wall of the uterus before childbirth, which causes severe bleeding that threatens the life of the mother and the fetus

Placental insufficiency- a disorder occurring during pregnancy in which the placenta does not function properly, causing the fetus to be deprived of nutrients

Placenta previa- a disorder in which the placenta develops at the lower section of the uterus (close to or covering the cervix); varies in severity, from no effect on a pregnancy to vaginal bleeding and danger to the mother and the fetus

Plague- a serious infectious disease transmitted to humans through bites of rodent fleas

Plantar reflex- the normal curling of the toes downward when the sole of the foot is stroked

Plantar wart- a rough-surfaced, hard spot on the sole of the foot that is caused by a virus

Plaque- an area of buildup of fat deposits in an artery, causing narrowing of the artery and possibly heart disease; dental plaque refers to a coating on the teeth, consisting of saliva, bacteria, and food debris, which causes tooth decay Plasma- the liquid part of the blood, containing substances such as nutrients, salts, and proteins

Plasma cell- a white blood cell that makes antibodies

Plasmapheresis- a procedure for removing unwanted substances from the blood in which blood is drawn, its plasma is separated and replaced, and the cleansed blood is returned to the body

Platelet- the smallest particle found in the blood, which plays a major role in forming blood clots

Pleura- the double-layered membrane that lines the lungs and chest cavity and allows for lung movement during breathing

Pleural effusion- a buildup of fluid between the membranes that line the lungs and chest cavity (the pleura); causes compression of the lungs, which leads to breathing difficulty

Pleural membranes- the pleura

Pleural rub- a rubbing sound produced by inflamed pleural membranes that can be heard when breathing

Pleural space- the space between the two layers of the pleura

Pleurisy- inflammation of the lining of the lungs and chest cavity, usually caused by a lung infection; characterized by sharp chest pain

Pleurodynia- pain in the chest caused by a virus

Plummer-Vinson syndrome- difficulty swallowing due to an abnormal web of tissue across the upper part of the esophagus

PMS- see Premenstrual syndrome

Pneumoconiosis- a respiratory disease caused by dust inhalation

Pneumocystis pneumonia- an opportunistic infection of the lungs caused by a single-celled parasite

Pneumonectomy- surgical removal of a lung

Pneumonia- inflammation of the lungs due to a bacterial or viral infection, which causes fever, shortness of breath, and the coughing up of phlegm

Pneumothorax- a condition in which air enters the space between the chest wall and the lungs, causing chest pain and shortness of breath; may occur spontaneously or be the result of a disease or an accident

Poliomyelitis- an infectious disease caused by a virus; usually causes only mild symptoms but in rare cases can attack the brain and spinal cord and cause paralysis or death

Polyarthritis- arthritis occurring in more than one joint

Polycystic kidney disease- a condition in which there are multiple, slow-growing cysts on both kidneys

Polycystic ovary syndrome- a hereditary disease characterized by multiple cysts on the ovaries, obesity, excessive hairiness, infertility, and irregular menstruation

Polycythemia- an increased amount of red blood cells in the blood

Polydactyly- the presence of an excessive number of fingers or toes

Polydipsia- excessive thirst

Polymyalgia rheumatica- a rare disease of the elderly, characterized by muscle stiffness and pain in the hips, thighs, shoulders, and neck

Polymyositis- an autoimmune disease of connective tissue in which muscles weaken and become inflamed

Polyp- a growth that occurs on mucous membranes such as those in the nose and intestine; bleeds easily and can become cancerous

Polysaccharide- a complex carbohydrate composed of three or more simple carbohydrate molecules joined together

Polyunsaturated fat- a fat or oil that contains well below the maximum number of hydrogen atoms possible; thought to reduce the risk of coronary heart disease

Polyuria- the excessive production of urine; can be a symptom of various diseases, most notably diabetes mellitus

Porphyria- a group of genetic disorders in which substances called porphyrins build up in the blood, often causing rashes brought on by exposure to sunlight and reactions to certain drugs

Portal hypertension- increased blood pressure in the portal vein

Portal vein- the vein connecting the stomach, intestines, and spleen to the liver

Positron emission tomography scanning- an imaging method in which substances emitting

positrons (positively charged particles) are introduced into the body, and detectors connected to a computer are used to form images of the tissues

Postcoital contraception- the prevention of pregnancy after sexual intercourse has occurred

Posterior- describes something that is located in or relates to the back of the body

Postmenopausal bleeding- bleeding from the vagina that occurs after menopause

Postmortem examination- examination of a body after death to determine the cause of death; commonly called an autopsy

Postmyocardial infarction syndrome- a condition that occurs following a heart attack or heart surgery; characterized by fever, chest pain, pericarditis, and pleurisy

Postnatal- describes something that occurs after birth, usually to the baby

Postpartum- a term that describes something that occurs after childbirth, usually to the mother

Post-traumatic stress disorder- feelings of anxiety experienced after a particularly frightening or stressful event, which include recurring dreams, difficulty sleeping, and a feeling of isolation

Postural drainage- drainage of mucus from specific areas of the lungs by placing the body in a specific position

Postural hypotension- unusually low blood pressure that occurs after suddenly standing or sitting up

Potassium- a mineral that plays an important role in the body, helping to maintain water balance, normal heart rhythm, conduction of nerve impulses, and muscle contraction

Precancerous- describes a condition from which cancer is likely to develop Precordial movement- movement of the heart that is seen and felt through the chest wall

Preeclampsia- a serious disorder that occurs in the second half of pregnancy, in which a woman experiences high blood pressure, fluid retention, nausea, and headaches; if not treated it can lead to eclampsia

Premature labor- labor that begins before the full term of pregnancy (about 37 weeks)

Premature rupture of membranes- the rupture of the sac that holds the fluid surrounding the fetus before the full term of pregnancy (about 37 weeks)

Premedication- drugs, usually painkillers, taken 1 to 2 hours before surgery

Premenopausal- a term that describes the period of a few years in a woman's life just before menopause

Premenstrual syndrome- physical and emotional changes that occur in a woman 1 or 2 weeks before menstruation, at or after ovulation; characterized by irritability, tension, depression, and fatigue

Prenatal care- medical care of a pregnant woman and the fetus

Prenatal diagnosis- techniques used to diagnose abnormalities in a fetus

Prenatal testing- tests performed on a pregnant woman or her fetus to prevent or diagnose abnormalities

Prepared childbirth- a technique in which a pregnant woman tries to minimize use of pain-relief medications during childbirth by learning relaxation techniques Prepuce- the foreskin

Presbycusis- the loss of hearing that occurs naturally with age

Presbyopia- the loss of the ability to focus the eyes on near objects that occurs naturally with age, as a result of loss of elasticity of the lens of the eyes

Pressure point- specific points on the body where external pressure can be applied to prevent excessive arterial bleeding

Pressure sore- an ulcer (erosion) on the skin that is a result of being bedridden; commonly called a bedsore

Priapism- a painful, persistent erection without sexual arousal, requiring emergency treatment

Prickly heat- a rash involving small, red, itchy spots and a prickly sensation that usually appears where sweat builds up

Primary- a disease that began in the affected location

Prion- an agent that is believed to cause several degenerative brain diseases

Procidentia- severe prolapse of an organ

Proctalgia- pain in the rectum

Proctitis- inflammation of the rectum, which causes soreness and sometimes mucus and/or pus in the stool

Proctoscopy- examination of the rectum using a viewing instrument

Productive cough- a cough that brings up phlegm, which is the body's natural way of clearing blocked airways

Progeria- an extremely rare condition in which the body ages prematurely

Progesterone- a female sex hormone that plays many important roles in reproduction, including the thickening of the lining of the uterus during the menstrual cycle; and during pregnancy, the functioning of the placenta, and the initiation of labor

Prognosis- a doctor's probable forecast of the effects and outcome of a disease

Progressive muscular atrophy- gradual degeneration and weakening of muscles due to a degenerative spinal cord

Prolactin- a hormone released by the pituitary gland that is responsible for the development of breasts and milk production in females

Prolapse- the displacement of an organ from its normal position to a new one

Prolapsed disk- see Disk prolapse

Prophylactic- anything used to prevent disease

Proprioception- the body's system for determining its position relative to the outside world

Prostatectomy- the partial or complete surgical removal of the prostate gland

Prostate gland- an organ located under the bladder that produces a large part of the semen

Prostatism- symptoms caused by an enlarged prostate gland, including difficulty with urination

Prostatitis- inflammation of the prostate gland, usually due to a bacterial infection spread from the urethra

Prosthesis- an artificial replacement for a missing part of the body

Proteins- large molecules made up of amino acids that play many major roles in the body, including forming the basis of body structures such as skin and hair, and important chemicals such as enzymes and hormones

Prothrombin time- the time it takes for a sample of blood to clot after substances that speed clotting time have been added; used to measure the effect of anticoagulants

Proton pump inhibitor- a drug used to treat peptic ulcers that reduces the amount of gastric acid produced

Proto-oncogene- a gene that is normally inactive but can become a cancer-causing oncogene if made active

Protozoan- a simple, single-celled organism

Proximal- located nearer to a central point of reference on the body, such as the trunk

Pruritus- the medical term for itching

Pseudogout- a form of arthritis with symptoms similar to gout that results from the depositing of calcium salts in a joint

Pseudomembranous enterocolitis- severe inflammation of the colon as a result of antibiotic use by an immunocompromised individual

Psittacosis- a chlamydial infection resembling influenza that is spread to humans by the droppings of infected birds

Psoralens- drugs that contain chemicals derived from plants; used to treat the skin disorders psoriasis and vitiligo

Psoriasis- a skin disorder characterized by patches of thick, red skin often covered by silvery scales

Psoriatic arthritis- a form of arthritis that develops as a complication of the skin disorder psoriasis

Psychogenic- resulting from psychological or emotional disorders

Psychological- relating to the mind and the processes of the mind

Psychosis- a mental disorder in which a serious inability to think, perceive, and judge clearly causes loss of touch with reality

Psychosomatic- describes a physical condition that is influenced by psychological or emotional factors

Psychotherapy- the treatment of mental and emotional disorders using psychological methods, such as counseling, instead of physical means

Psychotic- relating to psychosis

Psychotropic drug- a drug that has a psychological effect

Ptosis- the drooping of the upper eyelid

Puberty- the period of time (usually between the ages of 10 and 15) during which sexual development occurs, allowing reproduction to become possible

Pubic louse- a small insect that lives in pubic hair, feeds on blood, and is usually spread by sexual contact; pubic lice are popularly called "crabs"

Pudendal block- a local anesthesia procedure used during childbirth, causing the lower part of the vagina to be insensitive to pain

Pudendum- the external genitals, usually referring to the female

Puerperal sepsis- infection of the female genital tract following childbirth, abortion, or miscarriage

Puerperium- the time period after childbirth (about 6 weeks) during which a woman's body returns to its normal physical state

Pulmonary artery- the artery that supplies the lungs with blood from the heart

Pulmonary edema- the buildup of fluid in lung tissue, which is usually caused by heart failure

Pulmonary embolism- blockage of the pulmonary artery by a floating mass in the blood

Pulmonary fibrosis- a condition in which the tissue of the lungs has become thick and scarred, usually because of inflammation caused by lung conditions such as pneumonia or tuberculosis

Pulmonary heart valve- the heart valve that stops blood pumped to the lungs from leaking back into the heart

Pulmonary hypertension- increased blood pressure in the arteries supplying blood to the lungs; caused by increased resistance to blood flow in the lungs, usually a result of a lung disease

Pulmonary insufficiency- a rare defect in the pulmonary heart valve in which it fails to close properly after each muscle contraction, allowing blood to leak back into the heart; weakens the heart's pumping ability

Pulmonary stenosis- obstruction of the flow of blood from the heart to the lungs

Pulp- the soft tissue inside of a tooth that contains blood vessels and nerves

Pulse- the expansion and contraction of a blood vessel due to the blood pumped through it; determined as the number of expansions per minute

Pupil- the opening at the center of the iris in the eye that constricts (contracts) and dilates (widens) in response to light

Purpuric rash- areas of purple or reddish-brown spots on the skin, which are caused by bleeding from underlying tissues

Pus- a thick, yellowish or greenish fluid that contains dead white blood cells, tissues, and bacteria; occurs at the site of a bacterial infection

Pustule- a small blister containing pus

PUVA- a form of phototherapy that combines the use of psoralens and ultraviolet light to treat skin disorders

Pyelolithotomy- surgical removal of a kidney stone

Pyelonephritis- inflammation of the kidney, usually due to a bacterial infection

Pyloric sphincter- a circular muscle located at the junction of the stomach and small intestine that controls the passage of food into the small intestine

Pyloric stenosis- narrowing of the outlet located at the junction of the stomach and small intestine

Pyloroplasty- surgical widening of the outlet between the stomach and small intestine

Pyrexia- a body temperature of above 98.6°F in the mouth or 99.8°F in the rectum

Pyrogen- any substance that causes a fever

Pyuria- the presence of white blood cells in the urine; usually an indication of kidney or urinary tract infection

Q

Quadriceps muscle- the muscle (consisting of 4 distinct parts) located at the front of the thigh that straightens the leg

R

Rabies- an infectious viral disease primarily affecting animals; can be transmitted to humans through an infected animal's bite; if untreated, can result in paralysis and death

Radial keratotomy- a surgical procedure for correcting nearsightedness in which tiny cuts are made in the cornea to change its shape and focusing properties

Radiation- a variety of types of energy, such as X-rays and ultraviolet

Radiation therapy- treatment of a disease, such as cancer, using forms of radioactivity that damage or destroy abnormal cells

Radical surgery- treatment of disease by surgically removing all tissue that is or may be affected

Radiculopathy- any disease of the nerve roots; can be caused by disk prolapse, arthritis, and other problems

Radioallergosorbent test- a blood test performed to help determine the cause of an allergy by detecting the presence of antibodies to various allergens

Radiography- the formation of images of the inside of the body using radiation projected through the body and onto film; a radiograph is also called an X-ray

Radionuclide scanning- an imaging technique in which a radioactive substance is introduced into the body and its emitted radiation is detected; specific organs can be studied according to the amount of the radioactive substance that they absorb

Radius- one of the two long bones of the forearm, located on the thumb side of the arm

Radon- a colorless, odorless, tasteless radioactive gas that is produced by materials in soil, rocks, and building materials; suspected of causing cancer

Rales- abnormal crackling or bubbling sounds heard in the lungs during breathing

Rash- an area of inflammation or a group of spots on the skin

Raynaud's disease- a condition in which the fingers and toes become pale when exposed to cold or emotional stress, owing to sudden narrowing of the arteries that supply them with blood

Receptor- a nerve cell that responds to a stimulus and produces a nerve impulse; also refers to the area on the surface of a cell that a chemical must bind to in order to have its effect

Recessive gene- a gene that does not produce its effect when it occurs with a dominant gene, but produces its effect only when there are two copies of it

Reconstructive surgery- surgery to rebuild part of the body that has been damaged or defective from birth

Rectal prolapse- bulging of the lining of the rectum through the anus, usually due to straining during a bowel movement

Rectum- a short tube located at the end of the large intestine, which connects the intestine to the anus

Red blood cell- a doughnut-shaped blood cell that carries oxygen from the lungs to body tissues

Reduction of fracture- the realignment of the broken ends of a bone Referred pain- pain felt in a part of the body remote from the site where pain originates

Reflex- an automatic, involuntary response of the nervous system to a stimulus

Reflux esophagitis- the backflow of gastric acid from the stomach to the lower esophagus, owing to a defect in the valve that separates them

Regurgitation- the backflow of fluid; can refer to food and drink flowing back up from the stomach into the mouth or blood flowing back into the heart through a defective heart valve

Rehabilitation- treatment for an injury or illness aimed at restoring physical abilities

Rehydration- treatment for dehydration (an abnormally low level of water in the body) in which levels are restored by taking fluids containing water, salt, and glucose by mouth or, if severe, through a vein

Reiter's syndrome- a disorder characterized by inflammation of the joints, urethra, and sometimes the conjunctiva

Relapse- the return of a disease or symptom after it had disappeared

Remission- the temporary disappearance of a disease or its symptoms, either partially or completely; also refers to the time period in which this occurs

REM sleep- rapid eye movement sleep; the stage of sleep in which dreaming occurs

Renal cell carcinoma- the most common type of kidney cancer

Renal colic- severe pain on one side of the lower back, usually as a result of a kidney stone

Renal tubular acidosis- inability of the kidneys to remove sufficient amounts of acid from the body, making the blood more acidic than normal

Renin- an enzyme that plays a role in increasing a low blood pressure

Repetitive strain injury- an injury that occurs when the same movement is repeated continuously

Reproductive system- the organs and structures that allow men and women to have sexual intercourse and produce children

Resection- partial or complete surgical removal of a diseased organ or structure

Respiration- the process by which oxygen is taken in and used by tissues in the body and carbon dioxide is released

Respirator- another term for a ventilator

Respiratory arrest- a condition in which a person suddenly stops breathing

Respiratory distress syndrome- a condition experienced after an illness or injury damages the lungs, causing severe breathing difficulty and resulting in a life-threatening lack of oxygen in the blood

Respiratory failure- the failure of the body to exchange gases properly, which leads to a buildup of carbon dioxide and a lack of oxygen in the blood

Respiratory system- the organs that carry out the process of respiration

Resting pulse- the pulse rate when a person is not experiencing any physical activity or mental stress

Reticulocyte- an immature red blood cell

Retina- a membrane lining the inside of the back of the eye that contains light-sensitive nerve cells that convert focused light into nerve impulses, making vision possible

Retinal artery occlusion- obstruction of an artery that supplies blood to the retina, resulting in some degree of temporary or permanent blindness

Retinitis pigmentosa- gradual loss of the field of vision, owing to a degeneration of the light-sensitive nerve cells of the retina

Retinoblastoma- a hereditary, cancerous tumor of the retina affecting infants and children

Retinoid- a substance resembling vitamin A that is used to treat skin conditions such as acne and has been reported to reduce skin wrinkling

Retinopathy- any disease or disorder of the retina; usually refers to damage to the retina caused by high blood pressure or diabetes mellitus

Retinoscopy- a method of determining focusing errors of the eye in which light is shined through the pupil and the reflected beam is measured

Retroviruses- a group of viruses that are made up of RNA instead of DNA, including HIV and the virus that causes T-cell leukemia

Reye's syndrome- a rare disorder mainly affecting those under the age of 15 that is characterized by brain and liver damage following a viral infection such as chickenpox or the flu; may be linked to taking aspirin to treat a viral infection

Rh blood group- a blood group classifying whether the substances called Rhesus (Rh) factors are present on the surface of red blood cells; the "positive" or "negative" designation in blood classification (for example, "O negative")

Rheumatic fever- a disorder that follows a throat infection by the streptococcus bacteria and causes inflammation in body tissues

Rheumatoid arthritis- a condition in which joints in the body become inflamed, stiff, painful, and sometimes deformed because of the body's own immune system attacking the tissues

Rheumatoid factors- antibodies that are present in about 80% of people with rheumatoid arthritis; their detection through blood testing can help to diagnose the disorder

Rh immunoglobulin- a substance used to prevent a woman who is Rh incompatible with her fetus from becoming Rh sensitized

Rh incompatibility- a condition in which a pregnant woman's Rh factor does not match that of the fetus; can lead to the production of antibodies by the mother that destroy the fetus' red blood cells

Rhinitis- inflammation of the mucous membrane lining the nose, which can cause sneezing, runny nose, congestion, and pain; when caused by substances in the air, it is called allergic rhinitis or hay fever

Rhinophyma- a bulb-shaped deformity and redness of the nose as a result of severe rosacea

Rhinoplasty- surgery that changes the structure of the nose, either to improve appearance or to correct a deformity or injury

Rh sensitized- a condition in which a woman who has a negative Rh factor develops permanent antibodies against Rh-positive blood as a result of exposure to the blood of her fetus; can cause fetal hemolysis in subsequent pregnancies

Rhythm method- a method of preventing pregnancy in which a couple does not have sexual intercourse during the days of the menstrual cycle during which fertilization can occur

Riboflavin- a vitamin belonging to the vitamin B complex that is important in many processes in the body and helps to maintain healthy skin

Rickets- a childhood disease in which bones lack calcium and are deformed as a result of vitamin D deficiency (vitamin D helps the body absorb calcium)

Rigor mortis- the stiffness that occurs in the body after death

Ringworm- a skin infection caused by a fungus that spreads out in an even circle, characterized by ring-like, scaly patches of red skin

Rinne's test- a test that uses a tuning fork to diagnose hearing loss resulting from poor conduction of sound from the outer to the inner ear

RNA- ribonucleic acid, which helps to decode and process the information contained in DNA

Rocky mountain spotted fever- a rare disease transmitted to humans through the bites of ticks; characterized by small pink spots on the wrists and ankles that spread to other parts of the body, become larger, and bleed

Rosacea- a skin disorder that is characterized by patches of red skin on the nose and cheeks and acne-like bumps; most commonly occurs in middle-aged women

Roseola infantum- a common disease in young children characterized by a sudden fever and rash

Rotator cuff- a structure made up of four muscle tendons that reinforces the shoulder joint

Roundworm- a group of worms that includes many of the major human parasites

Rubella- a mild viral infection (also known as German measles) that produces a rash and fever; dangerous when it infects a woman during the early stages of pregnancy, when it can spread causing birth defects in the fetus

Rubeola- another term for measles

Rupture- a tear or break in an organ or tissue

S

Saccharides- a group of carbohydrates, including sugars and starches

Sacroiliac joints - the pair of joints located in the pelvis between the sacrum and the hipbones

Sacroiliitis- inflammation of the sacroiliac joints, which causes pain in the lower body

Sacrum- the triangular bone located at the bottom of the spine that is connected to the tailbone, the hipbones near the sacroilial joints, and the rest of the spine

SADS- see Seasonal affective disorder syndrome

Safe sex- measures taken to reduce the risk of acquiring a sexually transmitted disease, such as the use of a condom

Saline- a salt solution or any substance that contains salt

Salivary glands- a group of glands that secrete saliva into the mouth

Salmonella- a group of bacteria; includes a species that causes food poisoning and another responsible for typhoid fever

Salmonellosis- infection by salmonella bacteria

Salpingectomy- surgical removal of one or both fallopian tubes

Salpingitis- inflammation of a fallopian tube

Salpingography- X-ray examination of the fallopian tubes

Salpingolysis- removal of abnormal scar tissue between a fallopian tube and nearby tissue

Salpingo-oophorectomy- the surgical removal of one or both of the fallopian tubes and one or both of the ovaries

Salpingostomy- surgical opening of a fallopian tube for drainage or removal of an obstruction

Sarcoidosis- a rare disease with no known cause that leads to inflammation in tissues throughout the body, including the lymph nodes, lungs, liver, skin, and eyes

Sarcoma- a cancer in connective tissue, fibrous tissue, or blood vessels

Saturated fat- fats that contain the maximum amount of hydrogen possible, such as those found in meats and dairy products; can contribute to coronary heart disease and the development of some cancers

Saturday night palsy- temporary paralysis of the arm after extended pressure on a nerve in the armpit

Scabies- a highly contagious skin disorder caused by a mite that burrows into the skin and produces an intense, itchy rash

Scarlet fever- an infectious childhood disease, caused by a streptococcus bacteria, that leads to a sore throat, fever, and rash

Schistosomiasis- infestation by a parasitic blood worm that can damage the liver, bladder, and intestines

Schizophrenia- a group of mental disorders characterized by abnormal thoughts, moods, and actions; sufferers have a distorted sense of reality, and a split personality (thoughts do not logically fit together)

Schönlein-Henoch purpura- inflammation and leakage of blood vessels, causing a rash

Sciatica- pain along the sciatic nerve, which runs down the length of the leg to the foot; usually caused by pressure on the nerve due to disk prolapse or a tumor, abscess, or blood clot

Sclera- the tough, white coating that covers and protects the inner structures of the eye

Scleroderma- an immune system disorder of varying degree that can affect many areas of the body

Sclerotherapy- treatment of varicose veins by injection of a solution that destroys them

Scoliosis- a condition in which the spine curves to one side and usually curves toward the opposite side in another section to compensate, producing a characteristic S shape

Screening- the testing of an otherwise healthy person in order to diagnose disorders at an early stage

Scrotum- the sac containing the testicles

Scurvy- a disease caused by a lack of vitamin C, characterized by weakness, bleeding and pain in joints and muscles, bleeding gums, and abnormal bone and tooth growth

Seasonal affective disorder syndrome- a type of depression that seems to be linked to shorter periods of daylight during the fall and winter

Sebaceous cyst- a swelling that occurs under the skin, most commonly on the scalp, face, ears, and genitals; although usually harmless, can grow very large and become painful if infected

Seborrhea- excessive oiliness of the face and scalp

Sebum- the oily, lubricating substance that is secreted by glands in the skin

Secondary- describes a disease or disorder that follows or is caused by another one

Sedatives- a group of drugs that have a calming effect; used to treat anxiety and pain, bring on sleep, and help relax a person before surgery

Seizure- sudden uncontrolled waves of electrical activity in the brain, causing involuntary movement or loss of consciousness

Selenium- an element needed by the body only in very small amounts that helps maintain tissue elasticity

Semen- fluid released during ejaculation that contains sperm along with fluids produced by the prostate gland and the seminal vesicles

Semen analysis- a procedure in which a semen sample is examined to determine the amount of sperm present, along with their shape and ability to move; commonly used in the treatment of male infertility

Seminal vesicles- two saclike glands in men that produce part of the fluid in semen Seminiferous tubules- coiled tubes inside of the testicle that are the site of sperm production

Seminoma- a type of testicular cancer that is made up of only a single type of cell

Senile plaques- abnormal deposits of a protein called amyloid in the brain; characteristic of Alzheimer disease

Sensorineural hearing loss- deafness caused by damage to the inner ear or the nerve that conducts signals from the ear to the brain

Sensory nerve- nerves that carry information about the body’s senses toward the brain

Sensory organ- an organ that receives and relays information about the body’s senses to the brain

Sepsis- the infection of a wound or tissue with bacteria, causing the spread of the bacteria into the bloodstream; now also known as systemic inflammatory response syndrome caused by a microbe

Septal defect- a birth defect in which a hole is present in the wall that separates the left and right sides of the heart

Septic arthritis- joint inflammation caused by a bacterial infection

Septicemia- a life-threatening condition in which bacteria multiply in the blood and produce toxic materials; commonly known as blood poisoning; now also known as systemic inflammatory response syndrome.

Septic shock- a life-threatening condition in which tissues become damaged and blood pressure drops due to bacteria multiplying and producing poisons in the blood

Serotonin- a chemical that transmits nerve impulses in the brain, causes blood vessels to constrict (narrow) at sites of bleeding, and stimulates smooth muscle movement in the intestines

Serum- the clear, watery fluid that separates from clotted blood

Sex chromosomes- the X and Y chromosomes that determine a person’s gender; women normally have two X chromosomes and men normally have one X and one Y

Sex hormones- hormones responsible for producing sex characteristics and controlling sexual functions

Sex-linked disorder- a disorder that is caused by genes located on the sex chromosomes

Sexually transmitted disease- infections that are most commonly spread through sexual intercourse or genital contact

Shigellosis- a bacterial infection of the intestines, causing abdominal pain and diarrhea

Shingles- a nerve infection caused by the chickenpox virus, causing areas of painful rash covered with blisters

Shin splints- pain and tenderness experienced in the lower leg as a result of damage or strain to leg muscles and tendons; usually caused by exercise

Shock- a reduced flow of blood throughout the body, usually caused by severe bleeding or a weak heart; without treatment, can lead to a collapse, coma, and death

Shunt- an artificially constructed or an abnormal passage connecting two usually separate structures in the body

Sickle cell anemia- a genetic disorder in which the red blood cells are abnormal and deformed, causing anemia (reduced ability to transport oxygen in the blood) and clogging of blood vessels; bouts of fever, headache, and weakness result

Sickle cell trait- a less serious form of sickle cell anemia Sick sinus syndrome- abnormal functioning of the structure that regulates the heartbeat, causing episodes of abnormal heart rhythm

SIDS- see Sudden infant death syndrome

Sigmoidoscopy- an examination of the rectum and the lowest part of the large intestine using a flexible viewing tube inserted through the anus

Silicone- a group of compounds of silicon and oxygen; commonly used as implants in cosmetic surgery because they resist body fluids and are not rejected by the body

Silicosis- a respiratory disease caused by inhalation of dust containing the mineral silica Single photon emission computed tomography- an imaging technique in which a radioactive substance is introduced into the body and the radiation emitted by the substance is detected by a camera and is transformed into cross-sectional images by a computer

Sinoatrial node- the structure that regulates the heartbeat; a natural "pacemaker"

Sinus- a cavity within bone or a channel that contains blood; also refers to an abnormal tract in the body

Sinus bradycardia- a regular heart rate of less than 60 beats per minute Sinusitis- inflammation of the lining of the cavities in the bone surrounding the nose (the sinuses), usually as a result of a bacterial infection spreading from the nose

Sinus rhythm- normal heart rhythm

Sinus tachycardia- a regular heart rate of over 100 beats per minute

Sjögren's syndrome- a condition characterized by dryness of the eyes, mouth, and vagina that tends to occur along with certain disorders of the immune system

Skin graft- a method of treating damaged or lost skin in which a piece of skin is taken from another area of the body and transplanted in a damaged or missing section

Skin patch- a sticky patch attached to the surface of the skin that releases drugs into the bloodstream

Skin patch test- a diagnostic test in which different allergens are taped to the skin to determine which causes an allergic reaction

Skin prick test- a test performed to determine a person’s sensitivity to a certain allergen by applying it to a small needle and using that needle to pierce the skin

Skull- the bones that form the framework of the head and enclose and protect the brain and other sensory organs

Sleep apnea- a condition in which breathing stops for very short periods of time during sleep

Sleeping sickness- an infectious disease in Africa spread by the bite of a tsetse fly that causes a fever and weakness

Slipped disk- the common term for disk prolapse

Small-cell carcinoma- the most serious form of lung cancer

Small intestine- the long tube running from the stomach to the large intestine that is involved in digestion of foods and absorption of nutrients

Smallpox- a highly contagious and often fatal viral infection that has been completely eradicated by immunization

Smear- a sample of cells spread across a glass slide to be examined through a microscope

Sodium- a mineral that plays a role in the body's water balance, heart rhythm, nerve impulses, and muscle contraction; present in table salt (sodium chloride)

Sodium bicarbonate- a substance used as an antacid

Solar plexus- the largest network of nerves in the body, located behind the stomach

Somatic- pertaining to the body

Spasm- an involuntary muscle contraction; can sometimes be powerful and painful

Spasticity- muscle stiffness caused by an increase in contractions of the muscle fibers

Spastic paralysis- spasticity involving partial paralysis

SPECT- see Single photon emission computed tomography

Speculum- an instrument that holds an opening of the body open so that an examination can be performed or a sample can be taken

Speech therapy- treatment to help someone overcome a problem communicating verbally

Sperm- the male sex cell produced in the testicles

Sperm antibody- an antibody against sperm that can be produced by a woman’s immune system

Spermatocele- a harmless cyst containing fluid and sperm that occurs in the tube through which sperm travel from the testicles

Sperm count- the amount of normally functioning sperm per some unit of semen; used to determine a man's fertility

Spermicide- a contraceptive substance that kills sperm

Sphincter- a ring of muscle fibers located around a naturally occurring passage or opening in the body that opens and closes to regulate passage of substances

Sphygmomanometer- an instrument used to measure blood pressure

Spider nevus- a collection of dilated (widened) capillaries on the skin that creates a patch resembling a spider

Spina bifida- a birth defect in which a section of the baby's spine fails to develop completely, leaving the spinal cord exposed in that section

Spina bifida occulta- the least dangerous form of spina bifida, in which bones in the spine fail to close but there is no protrusion of the spinal cord or its fluid cushion out of the body

Spinal cord- a long tube of nerve tissue inside the spinal column, running from the brain down the length of the back inside of the spine

Spinal fusion- the surgical joining of two or more adjacent vertebrae using bone fragments; used to help severe back pain or prevent damage to the spinal cord

Spinal tap- another term for a lumbar puncture

Spine- the column of bones and cartilage running along the midline of the back that surrounds and protects the spinal cord and supports the head

Spiral fracture- a coiled break in a bone, resembling a corkscrew

Spirometry- a test of lung condition; a person breathes into a machine called a spirometer that measures the volume of air exhaled

Spleen- an organ located in the upper left abdomen behind the ribs that removes and destroys old red blood cells and helps fight infection

Splenectomy- surgical removal of the spleen

Splint- a device that is used to immobilize a part of the body Splinter hemorrhage- a splinter-shaped area of bleeding under a fingernail or toenail

Spondylitis- inflammation of the joints between the bones of the spine

Spondylolisthesis- the slipping of a vertebra in the spine over the one below it

Spondylolysis- a disorder in which the lower part of the spine is weakened by an abnormally soft vertebra

Sporotrichosis- an infection with a fungus acquired through a skin wound; causes an ulcer at the site of infection and small, rounded masses of tissue near it

Sprain- the tearing or stretching of the ligaments in a joint, characterized by pain, swelling, and an inability to move the joint

Sprue- a digestive disorder in which nutrients cannot be properly absorbed from food, causing weakness and loss of weight

Sputum- mucus and other material produced by the lining of the respiratory tract; also called phlegm

Squamous cell carcinoma- a type of skin cancer arising from flat cells of the epithelium; can also affect the lungs, cervix, and esophagus

Stapedectomy- surgical removal of a stapes (a sound-conducting bone in the middle ear) that cannot move to transmit sound; performed to treat hearing loss caused by otosclerosis

Staphylococci- common bacteria that cause skin infections and a number of other disorders

Status asthmaticus- a life-threatening asthma attack requiring immediate treatment

Status epilepticus- a life-threatening succession of epileptic seizures

STD- see Sexually transmitted disease

Stein-Leventhal syndrome- see Polycystic ovary syndrome

Stem cells- cells that give rise to the different types of blood cells

Stenosis- narrowing of a body passageway

Stent- a device used to hold tissues in place, such as to support a skin graft

Stereotaxic surgery- brain surgery done through a small opening in the skull and guided by X-rays or computer-aided imaging techniques

Sterilization- a surgery performed to make a person incapable of reproducing; also refers to the process of killing microorganisms on objects such as surgical instruments

Sternum- the long, flat bone located at the center of the chest

Steroids- a group of drugs that includes corticosteroids, which resemble hormones produced by the adrenal glands, and anabolic steroids, which are similar to the hormones produced by the male sex organs

Stillbirth- a baby that is born dead after the 28th week of pregnancy; also called late fetal death

Stoma- a surgically formed opening on a body surface

Stomach bypass- a surgical procedure to treat an obstructed stomach or severe obesity in which the passage of food is diverted around the stomach and directly into the small intestine

Stomach stapling- a procedure in which the stomach is made smaller by partitioning it off using metal staples; used as an extreme treatment of severe obesity

Stool- another term for feces

Strabismus- a condition in which the eyes are not aligned correctly, such as cross-eye (one eye points inward) and walleye (one eye points outward)

Straight-leg raising- a simple test performed in a doctor’s office to check for disk prolapse

Strain- muscle damage resulting from excessive stretching or forceful contraction Strangulated hernia- a hernia in which the protruding organ or tissue loses its blood supply, requiring emergency surgery

Strawberry nevus- a bright red, raised birthmark that usually disappears without treatment

Strep throat- a throat infection caused by streptococcus bacteria; characterized by a sore throat, fever, and enlarged lymph nodes in the neck

Streptococci- bacteria that cause a variety of diseases, including pneumonia and strep throat

Stress fracture- a bone break resulting from repeated pressure on the bone

Stretch marks- lines on the skin that occur when the inner skin layer is stretched thin and loses its elasticity

Stroke- damage to part of the brain because of a lack of blood supply (due to a blockage in an artery) or the rupturing of a blood vessel; leads to complete or partial loss of function in the area of the body that is controlled by the damaged part of the brain

Stye- a pus-filled abscess in the follicle of an eyelash; caused by a bacterial infection

Subcutaneous- a medical term meaning "beneath the skin"

Submucosa- the layer of connective tissue under a mucous membrane

Suction lipectomy- see Liposuction

Sudden infant death syndrome- the unexpected, sudden death of an apparently healthy baby, the cause of which cannot be found; also called crib death

Suppository- a solid cone or bullet-shaped object made up of a chemically inactive substance and a drug that is inserted into the rectum or vagina; used to administer a drug

Suppuration- the production of pus

Surfactant- a mixture of substances secreted by the air sacs of the lungs that prevents the air sacs from collapsing during exhalation

Surrogate- a woman who agrees to become pregnant and give her baby to someone else when the child is born

Suture- a surgical stitch that helps close an incision or wound so that it can heal properly

Sweat glands- tiny structures in the skin that secrete sweat

Sweat test- a measure of the saltiness of sweat to help diagnose cystic fibrosis

Swimmer's ear- see Otitis externa

Sycosis barbae- a bacterial infection of the hair follicles in the beard area

Sympathetic nervous system- the part of the autonomic nervous system that raises blood pressure and heart rate in response to stress

Syndactyly- a condition in which fingers or toes are fused together

Syndrome- a group of symptoms that indicate a certain disorder when they occur together

Synovectomy- surgical removal of the synovial membrane

Synovial fluid- a lubricating fluid secreted by the synovial membrane

Synovial membrane- the thin membrane that lines the inside of a joint capsule

Synovitus- inflammation of the membrane lining a joint capsule as a result of injury or infection or due to a chronic illness such as rheumatoid arthritis; characterized by redness, swelling, stiffness, and pain

Syphilis- a sexually transmitted disease; initially causes only painless sores on the genitals but can be life-threatening if untreated

Systemic- affecting the whole body

Systemic inflammatory response syndrome- a condition characterized by having two of the following four clinical criteria: fever, rapid breathing, increased heart rate, and abnormal white blood cell count

Systemic lupus erythematosus- a disease of the immune system that causes inflammation of connective tissue in many areas of the body, including the skin, lungs, heart, joints, and kidneys

Systolic pressure- the blood pressure measured while the heart is contracting

T

Tachycardia- a rapid heart rate (over 100 beats per minute)

Tapeworm- a parasitic worm that lives in the intestines; causes diarrhea and abdominal discomfort

Tar- the sticky, brown substance in cigarettes that coats the lungs; causes lung and other cancers

Tarsorrhaphy- a procedure in which the eyelids are sewn shut; performed to protect the corneas

Tartar- the hard deposit formed on teeth when mineral salts in saliva combine with plaque; can cause dental problems such as gum disease if not controlled

Tay-Sachs disease- a severe genetic disorder that causes nervous system disturbances and death, usually before the age of 3

TB- see Tuberculosis

T cell- see T-lymphocyte

T-cell leukemia- a type of leukemia caused by a virus in which T-lymphocytes divide uncontrollably

Tear duct- a tiny passageway that drains lubricating tears from the surface of the eye to the back of the nose

Telangiectasia- redness of an area of skin, caused by enlargement and proliferation of the underlying small blood vessels

Temperature method- a natural method of family planning in which a woman determines her time of ovulation by changes in her daily temperature

Temporal arteritis- inflammation and narrowing of arteries in the head and neck, including those in the scalp near the temple, which can cause blindness if untreated

Temporomandibular joint syndrome- headache, facial pain, and jaw tenderness caused by irregularities in the way the joints, muscles, and ligaments in the jaw work together

Tendinitis- inflammation of a tendon, usually caused by injury, characterized by pain, tenderness, and sometimes limited movement in the attached muscle

Tendon- strong connective tissue cords that attach muscle to bone or muscle to muscle Tendon transfer- surgical cutting and repositioning of a tendon so that the muscle attached to it has a new function

Tennis elbow- a form of tendinitis that causes pain and tenderness in the elbow and forearm

Tenosynovitis- inflammation of the inner lining of the sheath that covers a tendon

Tenovaginitis- inflammation of the fibrous wall of the sheath that covers a tendon

TENS- see Transcutaneous electrical nerve stimulation

Tension headache- a headache caused by emotional strain or tension in the muscles of the head and neck

Teratogen- anything that causes abnormalities in a developing embryo or fetus, such as a drug or virus

Teratoma- a tumor composed of cells not normally found in the part of the body when the tumor occurred

Termination of pregnancy- see Abortion

Testicles- the two male sex organs that produce sperm and the sex hormone testosterone

Testicular feminization factor- a genetic disorder in which an individual who is genetically male has the external appearance of a female because the body is unresponsive to testosterone

Testicular torsion- severe pain and swelling of a testicle, due to twisting of the spermatic cord

Testosterone- the sex hormone that stimulates development of male sex characteristics and bone and muscle growth; produced by the testicles and in small amounts by the ovaries

Tetanus- a sometimes fatal disease affecting the brain and spinal cord; caused by infection with bacterium present in soil and manure

Tetracyclines- a group of antibiotic drugs used to treat a wide variety of infections, including bronchitis and some types of pneumonia

Tetralogy of Fallot- a genetic heart disease involving four structural defects in the heart, which result in insufficient levels of oxygen in the blood

Thalamus- a structure in the brain that relays and processes incoming sensory information from the eyes and ears and from pressure and pain receptors

Thalassemia- a group of genetic blood disorders characterized by a defect in the ability to produce hemoglobin, leading to the rupturing of red blood cells (called hemolytic anemia)

Thallium scanning- a type of radionuclide scanning used to assess the heart Therapeutic range- the range of doses of a drug that will produce beneficial results without side effects

Thoracoscopy- examination of the membranes covering the lungs using an endoscope

Thoracotomy- a procedure in which the chest is surgically opened to operate on an organ in the chest cavity

Thorax- the chest

Thrill- a vibration felt when the hand is placed flat on the chest; caused by abnormal blood flow through the heart as a result of disease

Thrombectomy- removal of a blood clot

Thrombocytopenic purpura- a decrease in the number of platelets in the blood, causing abnormal bleeding of blood vessels into the skin

Thromboembolism- blockage of a blood vessel by a blood clot fragment that has broken off and traveled from another area of the body

Thrombophlebitis- inflammation of a vein, along with clot formation in the affected area

Thrombosis- a condition in which a blood clot (thrombus) has formed inside a blood vessel

Thrombus- a blood clot in a blood vessel

Thrush- a candidiasis infection

Thymoma- a tumor of the thymus gland

Thymus gland- an immune system gland located in the upper part of the chest that plays an important role in the production of T-lymphocytes

Thyroglossal cyst- a swelling at the front of the neck; forms from a duct that fails to disappear during embryonic development

Thyroid gland- a gland located in the front of the neck below the voice box that plays an important role in metabolism (the chemical processes in the body) and growth; the gland produces thyroid hormone

Thyroiditis- inflammation of the thyroid gland

Thyrotoxicosis- a toxic condition resulting from overactivity of the thyroid gland

Thyroxin- a hormone produced by the thyroid gland that helps regulate energy production in the body

TIA- see Transient ischemic attack

Tibia- the thicker of the two long bones in the lower leg; commonly called the shin

Tic- an involuntary, repetitive movement such as a twitch

Tic douloureux- see Trigeminal neuralgia

Ticks- small, eight-legged animals that can attach to humans and animals and feed on blood; sometimes spread infectious organisms via their bites

Tietze's syndrome- inflammation of the cartilage that joins ribs to the breastbone, causing chest pain

Tinea- a group of common infections occurring on the skin, hair, and nails that are caused by a fungus; commonly referred to as ringworm

Tinnitus- a persistent ringing or buzzing sound in the ear

Tipped uterus- an abnormal condition in which the uterus is tilted backward instead of slightly forward

Tissue plasminogen activator- a substance produced by the body and as a genetically engineered drug to prevent abnormal blood clotting

Tissue typing- tests used to determine the compatibility of tissues used in grafts and transplants

T-lymphocyte- a type of white blood cell that fights infections and destroys abnormal cells directly; as compared with releasing antibodies to fight infection

T-lymphocyte killer cell- a type of T-lymphocyte white blood cell that attaches to abnormal cells and releases chemicals that destroy them

TMJ syndrome- see Temporomandibular joint syndrome

Tolerance- decreased sensitivity of the body to a certain drug, usually either because the liver becomes more efficient at breaking down the drug or the body's tissues become less sensitive to it; increased tolerance creates a need for a higher dose of the drug in order to have the same effects

Tonometry- the procedure used to measure the pressure within the eye; is useful in detecting glaucoma

Tonsillectomy- surgical removal of the tonsils, usually to treat tonsillitis

Tonsillitis- infection and inflammation of the tonsils

Tonsils- masses of lymphoid tissue located at either side of the back of the throat

Tourette's syndrome- a movement disorder characterized by involuntary tics and noises, and in some cases uncontrollable shouting of obscenities

Tourniquet- a device placed tightly around an arm or leg in order to stop blood flow; can be used to locate veins in order to take a blood sample or to control blood flow during some operations

Toxemia- the presence of bacterial toxins in the blood Toxic epidermal necrolysis- a severe rash in which the outer layers of skin blister and peel off

Toxicity- the extent to which a substance is poisonous

Toxic shock syndrome- a life-threatening condition caused by a staphylococci toxin

Toxin- a poisonous substance

Toxocariasis- human infestation with the larvae of a worm found in the intestines of dogs

Toxoplasmosis- a common protozoan infection that is usually only dangerous to a fetus in early pregnancy or a person who is immunocompromised

TPA- see Tissue plasminogen activator

Trachea- the tube running from the larynx (the voice box) down the neck and into the upper part of the chest, where it divides to form the two bronchi of the lungs; commonly called the windpipe

Tracheitis- inflammation of the trachea

Tracheotomy- insertion of a tube through a surgical opening in the trachea to maintain an open airway

Trachoma- a persistent, contagious form of conjunctivitis that can lead to complications such as blindness if untreated

Traction- the use of tension to hold a body part in place or to correct or prevent an alignment problem

Transcutaneous- through the skin

Transcutaneous electrical nerve stimulation- a method of relieving pain by applying tiny electrical impulses to nerve endings beneath the skin

Transferrin- a substance in the blood that transports iron throughout the body

Transient ischemic attack- a temporary block in the supply of blood to the brain, resulting in temporary loss of sensation, movement, vision, or speech; often called mini-strokes and can be precursors to a real stroke

Transmissible- able to be passed from one organism to another

Transplant- transferring a healthy tissue or organ to replace a damaged tissue or organ; also refers to the tissue or organ transplanted

Transurethral prostatectomy- removal of cancerous tissue from the prostate gland using a resectoscope (a long, narrow instrument passed up the urethra), which allows the surgeon to simultaneously view the prostate and cut away the cancerous tissue

Trauma- physical injury or emotional shock

Travelers' diarrhea- diarrhea when traveling in a foreign country, caused by contaminated food or water

Tremor- an involuntary, rhythmic, shaking movement caused by alternating contraction and relaxation of muscles; can be the normal result of age or the abnormal effect of a disorder

Triage- a system used to classify sick or injured people according to the severity of their conditions

Trichiasis- growth of the eyelashes inward toward the cornea, causing persistent irritation of the eyeball

Trichinosis- infestation by the larvae of the parasitic worm Trichinella spiralis, usually acquired by eating undercooked pork

Trichomoniasis- infection of the vagina by the single-celled parasite Trichomonas vaginilis, which may cause inflammation, itchiness, and discharge from the vagina

Tricuspid valve- the valve located between the two left chambers of the heart (the left atrium and the left ventricle)

Tricyclic antidepressants- drugs used in the treatment of clinical depression

Trigeminal neuralgia- a disorder of the trigeminal nerve (a cranial nerve) that causes brief attacks of severe pain in the lips, cheeks, gums, or chin on one side of the face

Triglyceride- the main form of fat in the blood; determining levels of triglyceride is useful in diagnosing and treating diabetes, high blood pressure, and heart disease

Trimester- one of three periods lasting about 3 months each; the stages into which pregnancy is divided

Triple X syndrome- the presence of an extra X chromosome in a woman, which may cause some degree of mental retardation

Trismus- the medical term for lockjaw

Trisomy- the presence in the cells of three copies of a certain chromosome instead of the normal two copies

Trisomy 21- see Down syndrome

Tubal ligation- a procedure in which the fallopian tubes are cut and tied off; usually a permanent form of sterilization

Tubal pregnancy- a pregnancy that occurs in the fallopian tubes, with a fertilized egg implanting in the tube instead of the uterus; severely painful and can be fatal if not detected and treated

Tuberous sclerosis- a genetic disorder of the skin and nervous system characterized by epilepsy, mental retardation, and a skin condition resembling acne

Tuboplasty- surgical repair of a damaged fallopian tube to treat infertility

Tumor- an abnormal mass that occurs when cells in a certain area reproduce unchecked; can be cancerous (malignant) or noncancerous (benign)

Tunnel vision- loss of peripheral vision so that only objects directly ahead can be seen; most commonly due to damage caused by increased pressure within the eye (glaucoma)

Turner's syndrome- a genetic disorder in women in which only one X chromosome is present, or both chromosomes are present but one is defective

Tympanic membrane- the medical term for the eardrum

Tympanoplasty- a surgical procedure used to treat hearing loss in which the eardrum or structures in the middle ear are repaired

Typhoid fever- an acute bacterial infection causing fever, headache, abdominal discomfort, and enlargement of the liver and spleen

Typhus- a group of diseases caused by the microorganism rickettsia, spread by the bites of fleas, mites, or ticks; symptoms include headache, fever, rash, and a series of complications if untreated

U

Ulcer- an open sore that occurs on the skin or on a mucous membrane because of the destruction of surface tissue

Ulcerative colitis- a chronic condition in which ulcers occur on the mucous membrane lining of the colon (the end of the large intestine) and the rectum

Ultrasound scanning- an imaging procedure used to examine internal organs in which high-frequency sound waves are passed into the body, reflected back, and used to build an image; also sometimes called sonography Ultraviolet light- a form of invisible light in sunlight that is responsible for the tanning and burning of skin and can cause cataracts and skin cancer

Umbilical cord- the tubal structure (consisting of two arteries and one vein) that connects the fetus to the placenta, supplying the fetus with oxygen and nutrients and removing some waste products

Umbilical hernia- a condition present at birth in which a part of the baby's intestines bulge through a weak area of the abdominal wall, creating a swelling around the navel

Unconsciousness- a temporary or prolonged loss of awareness of self and of surroundings

Undescended testicle- a testicle that has not moved down from the abdomen, where it develops, into the scrotum

Unsaturated fat- a fat or oil found mainly in vegetables; thought to reduce the risk of coronary heart disease

Urea- a waste product of the metabolism of proteins that is formed by the liver and secreted by the kidneys

Uremia- abnormally high levels of waste products such as urea in the blood

Ureters- two tubes that carry urine from the kidneys to the bladder

Urethra- the tube by which urine is released from the bladder

Urethritis- inflammation of the urethra

Urethrocele- a bulging of the urethra into the vagina

Urethrocystitis- inflammation of the urethra and the bladder

Urinalysis- a group of physical and chemical tests done on a sample of urine to check for various disorders, including those of the kidneys and urinary tract

Urinary diversion- an operation to allow urine passage when the bladder or urethra has become blocked or been removed

Urinary incontinence- the involuntary release of urine because of the inability to control bladder muscles; may occur as a natural part of the aging process or be caused by an injury or disorder

Urinary tract- the structures in the body that are responsible for the production and release of urine, including the kidneys, ureters, bladder, and urethra

Urticaria- an allergic reaction in which itchy white lumps surrounded by areas of inflammation appear on the skin; commonly called "hives"

Uterine prolapse- a condition in which the uterus moves downward into the vagina due to a weakness of the ligaments and muscles that hold the uterus in place

Uterus- the hollow female reproductive organ in which a fertilized egg is implanted and a fetus develops

Uvea- a structure consisting of the colored area of the eye and the middle layer of the eye that contains blood vessels

Uveitis- inflammation of the uvea

V

Vaccination- a form of immunization in which killed or weakened microorganisms are placed into the body, where antibodies against them are developed; if the same types of microorganisms enter the body again, they will be destroyed by the antibodies

Vaccine- a preparation of weakened microorganisms given to create resistance to a certain disease

Vacuum aspiration- removal of the contents of the uterus using a suction device

Vacuum extraction- a technique used to facilitate childbirth using a suction device to help move the baby through the birth canal

Vagina- the muscular passage connecting the uterus with the outside genitals; a component of the female reproductive system

Vaginismus- an involuntary muscle spasm at the opening of the vagina when sexual intercourse is attempted; can be quite painful and may make sexual intercourse nearly impossible

Vaginitis- inflammation of the vagina, which can be the result of infection, aging, a hormone deficiency, or a foreign object (such as a tampon)

Valve- a structure that allows fluid flow in only one direction

Valvotomy- surgical correction of a narrowed heart valve

Valvular heart disease- a heart valve defect

Valvuloplasty- reconstruction or repair of a narrowed heart valve

Varicella- the medical term for chickenpox

Varices- enlarged or twisted blood or lymph vessels

Varicocele- the appearance of varicose veins around the testicles; commonly occurs and is harmless, but may cause discomfort

Varicose veins- enlarged, twisted veins just below the surface of the skin, caused by defective valves in the veins

Variola- another term for smallpox

Vascular- pertaining to blood vessels

Vasculitis- inflammation of blood vessels

Vas deferens- a thin tube that stores and transports sperm

Vasectomy- a usually permanent method of sterilization in which the tubes carrying sperm from the testicles (the vas deferens) are cut and tied off; as a result, the semen will no longer contain sperm

Vasoconstriction- narrowing of blood vessels

Vasodilation- widening of blood vessels

Vasovagal attack- a sudden slowing of the heart, causing fainting

VD- see Venereal disease

Vein- a blood vessel that carries blood toward the heart

Venereal disease- any disease that is usually spread through sexual intercourse or genital contact

Venipuncture- piercing of a vein with a hollow needle to inject fluid or withdraw blood

Venography- an X-ray procedure for viewing veins

Venom- a poisonous substance produced by certain animals

Ventilation- the process through which oxygen and carbon dioxide are exchanged between the lungs and the air; also refers to the use of a machine to carry out this process in someone who cannot breathe on his or her own

Ventilator- a machine used to take over breathing when a person cannot breathe on his or her own

Ventricle- a small cavity or chamber; there are four ventricles in the brain that circulate cerebrospinal fluid through it, and two in the heart that pump blood throughout the body

Ventricular fibrillation- rapid, irregular contractions of the heart

Ventricular septal defect- a hole in the wall that separates the two lower chambers of the heart (called the ventricles)

Vernix- the thick, greasy substance that covers the skin of a newborn baby

Version- a shift in the position of the fetus inside of the uterus, either occurring naturally or as performed by a doctor to facilitate delivery

Vertebra- any one of the 33 bones that make up the spine

Vertebral arteries- a pair of arteries running up the neck to supply the brain with blood

Vertebrobasilar insufficiency- episodes of dizziness and weakness caused by insufficient blood flow to the brain

Vertex presentation- the usual, head-first presentation of the fetus during delivery

Vertigo- the feeling that one or one's surroundings are spinning

Very low-density lipoprotein- a class of blood proteins, a high level of which is associated with coronary heart disease

Vesicle- a small skin blister, or any sac in the body, that contains fluid

Vestibular glands- two small glands located at the opening of the vagina that secrete a lubricating fluid during sexual stimulation

Villi- the millions of fingerlike projections on the lining of the small intestine that aid in the absorption of food

Viral- a term describing something related to or caused by a virus

Viremia- the presence of viruses in the blood

Virilization- the process by which a woman develops male characteristics; caused by overproduction of male sex hormones

Virulence- the relative ability of an organism to cause disease

Virus- the smallest known disease-causing microorganism; viruses are very simple in structure and can only multiply when they are inside the cell of another organism

Visual acuity- a measure of the sharpness of a person's vision

Visual field- the area on both sides that can be seen while looking straight ahead

Vital sign- any sign, such as a pulse, that indicates that a person is alive

Vitamin A- a vitamin essential for normal growth and development of the body (most notably the bones and teeth), protection of mucous membranes from infection, normal vision, and healthy skin and hair

Vitamin B complex- a group of vitamins including thiamine, niacin, riboflavin, pantothenic acid, pyridoxine, biotin, and folic acid; plays a variety of important roles in the body, including in hormone production, metabolism, and functioning of the nerves, muscle, heart, and digestive system

Vitamin B6- a vitamin that plays an important role in the breakdown and use of energy sources, production of red blood cells and antibodies, and normal functioning of the nervous system

Vitamin B12- a vitamin that is essential to the production of DNA (the genetic material in cells) and red blood cells and in the functioning of the nervous system

Vitamin C- a vitamin with many essential roles, including in maintaining healthy bones, teeth, gums, ligaments, and blood vessels and in the immune system's response to infection

Vitamin D- a vitamin that plays a role in the absorption of calcium by the intestines and is essential for healthy bones and teeth

Vitamin E- a vitamin that protects tissues from damage by oxygen free radicals, helps to form red blood cells, maintains the function of enzymes, and maintains cell structure

Vitamin K- a vitamin that is essential for normal blood clotting and the body's absorption of calcium

Vitamins- complex substances that are necessary in small amounts to maintain health and ensure proper development and functioning of the body

Vitiligo- a condition in which patches of skin on the body lose their color; thought to be caused by the immune system attacking the skin tissues, causing the absence of melanin

Vitreous humor- the clear, watery fluid that fills the cavity of the eye behind the lens

VLDL- see Very low-density lipoprotein

Vocal cords- two strips of tissue in the voice box that have the ability to produce sound when air passing through them causes the tissues to vibrate

Volvulus- twisting and obstruction of an area of intestine

Von Willebrand's disease- a genetic disorder characterized by excessive bleeding

V/Q lung scans- images produced by radionuclide scanning of the lungs; used to help diagnose a pulmonary embolism

Vulva- the outer, visible portion of the female genitals

Vulvitis- inflammation of the vulva

Vulvovaginitis- inflammation of the vulva and vagina

W

Walleye- a condition in which one eye turns outward

Wart- a contagious, harmless growth caused by a virus that occurs on the skin or a mucous membrane

Weber's test- a test in which a vibrating tuning fork is held against the forehead to help determine the cause of hearing loss

Wegener's granulomatosis- a disorder in which nodules associated with inflammation of blood vessels develop in the lungs, kidneys, and nasal passageways

Weight-bearing exercise- exercise that puts stress on bones, such as walking, which helps build up bone density and prevent the bones from becoming brittle

Wernicke's encephalopathy- a brain disorder characterized by abnormal eye movements, difficulties with muscle coordination, and confusion; usually the result of chronic alcoholism

Wheeze- a high-pitched sound produced during breathing because of narrowing of the airways; common sign of asthma

Whiplash injury- injury to the ligaments, joints, and soft tissues of the neck region of the spine because of a sudden, violent jerking motion of the head

Whipple's disease- a rare disorder that has widespread effects on the body, including impaired absorption of nutrients, weight loss, joint pain, and anemia

Whipworm- a small, parasitic worm that can live in the intestines of a human and may cause diarrhea, abdominal pain, and anemia

White blood cell- a group of colorless blood cells that are part of the immune system, helping prevent and fight infection

White blood cell count- the number of white blood cells present in a blood sample; useful in diagnosing and evaluating various diseases and infections

Whitehead- a painless, small, white bump; usually occurs in groups on the nose, cheeks, or around the eyes

Whitlow- an abscess on the end of a finger or a toe that is caused by the herpes simplex virus or a bacterial infection

Whooping cough- see Pertussis

Wilm's tumor- a type of kidney cancer that usually affects children under the age of 5

Wilson's disease- a rare genetic disorder in which copper builds up in the liver and is released into other parts of the body, eventually causing damage to the liver and brain

Withdrawal bleeding- bleeding from the vagina that occurs when hormone levels drop, such as menstruation or the bleeding that occurs at the end of each cycle of the combined oral contraceptive pill

X

Xanthelasma- fatty deposits around the eyes that are common in elderly people and are associated with high levels of cholesterol in the blood

Xanthine- a bronchodilator drug that is used to treat asthma

Xanthomatosis- a condition in which fatty deposits occur in various parts of the body, possibly leading to atherosclerosis

X chromosome- one of the two sex chromosomes; determines female sex characteristics

Xeroderma pigmentosum- a genetic disorder in which the skin is extremely sensitive to sunlight, causing it to age prematurely and leaving the individual particularly susceptible to skin cancer

Xerophthalmia- excessive dryness of the cornea and conjunctiva due to a lack of vitamin A

X-linked disorder- a genetic disorder in which the abnormal gene is located on the X chromosome; those affected are almost always men

X-ray- see Radiography

XYY syndrome- a disorder in which a man has an extra Y chromosome, causing him to be unusually tall and to have behavioral disorders

Y

Y chromosome- one of the two sex chromosomes; determines male sex characteristics

Yeast infection- a term usually referring to a candidiasis infection

Yellow fever- a life-threatening viral infection transmitted by mosquitoes that causes jaundice, fever, headache, and vomiting

Z

ZIFT- see Zygote intrafallopian transfer

Zinc chloride- a white powder used as an antiseptic and antiperspirant

Zollinger-Ellison syndrome- a rare disorder in which tumors form in the pancreas and secrete the hormone gastrin, which causes increased production of gastric acid and recurrent peptic ulcers

Zoonosis- a parasite-caused or infectious disease in animals that can be transferred to humans

Zygote- the cell that results when an egg is fertilized by a sperm

Zygote intrafallopian transfer- a method used to treat infertility in which an egg fertilized outside the body is placed into a woman's fallopian tube
Sex Glossary Sex Glossary