Glossary - A

Abortifacient
Induces expulsion of an embryo or foetus.
Acetylcholine
A neurotransmitter that slows heart rate; controlled by the parasympathetic nervous system.
Achlorhydria
The absence or insufficiency of hydrochloric acid from the gastric juice; this results in insufficient digestion.
Acidosis
Excess acidity in the body, as may result for example from diabetes and kidney disease. This usually causes the pH of the blood to drop.
Acrid
Sharp and harsh, or bitter and unpleasant tasting; causing heat and irritation; corrosive, caustic.
Adaptogen
A substance that is "innocuous, causing minimal physiological disorder; non-specific in action, increasing resistance to the adverse influences of a wide range of physical, chemical and biological factors; and capable of a normalizing action irrespective of the direction of the pathological change." Adaptogens are said to help adapt people to stress, thereby preventing many chronic degenerative diseases. The validity of the concept is debatable.
Addison's disease
A destructive disease characterized by deficient secretion of the adrenal hormones aldosterone and cortisol, and weakness, loss of weight, low blood pressure, gastrointestinal disturbances and brownish pigmentation of the skin and mucous membranes.
Adenitis
Inflammation of a gland. Often specifically the inflammation of lymph nodes or tissues.
Adenoid (usually plural, adenoids)
An enlarged body of lymphoid tissue at the back of the pharynx, which may obstruct breathing.
Adenopathy
Glandular disease (a general term).
Adrenalin
See Epinephrine.
Adrenaline
A trademark for a preparation of adrenalin.
Adrenergic
See Sympathomimetic.
Aerophagia
The swallowing of air, particularly in hysteria.
Aesthesia
Perception and feeling, the opposite of anaesthesia.
Agalactia (agalactosis)
Absence or failure of the secretion of milk.
Ague
A fever accompanied by chills and sweating that recurs at regular intervals (as with malaria); a fit of shivering.
Albuminuria
Presence of protein in the urine, principally albumin, generally indicating disease.
Alexiteric
Antidotal, especially to snakebites.
Alkaloid
One of a large group of nitrogenous substances found naturally in plants. These are alkaline, and react with acids to form salts. They are usually very bitter and although often poisonous, may have pharmacological value. Examples: atropine, berberine, caffeine, coniine, morphine, nicotine, quinine, strychnine. The term is also applied to similar synthetic substances such as procaine.
Allergen
A substance that can cause an allergic reaction (for example, pollen, dander, mold spores).
Allergy
Hypersensitivity of the immune system to exposure to given substances (antigens) such as pollen, bee stings, poison ivy, drugs, or foods. In response, the body summons antibodies (immunoglobulin E) to fight the allergens. Special cells called mast cells are frequently inadvertently injured, releasing a variety of chemicals including histamine into the tissues and blood that frequently cause allergic reactions. These irritating chemicals may produce itching, swelling, muscle spasm, and lung and throat tightening as is found in asthma. Anaphylactic shock is a severe form of allergy response (symptoms include dizziness, loss of consciousness, labored breathing, swelling of the tongue and breathing tubes, blueness of the skin, low blood pressure, and death).
Allopathy
  1. A system of medicine combatting disease by remedies producing effects different from those produced by the disease treated;
  2. A system of medicine using all measures proven of value in treating disease. A term invented by S. Hahnemann to designate the ordinary practice of medicine, as opposed to homeopathy.
Alopecia
Baldness.
Alterative
Gradually restores healthy functions; a very general and rather vague term.
Amaurosis
Blindness, often the result of a cortical lesion or from no change in the eye itself.
Amblyopia
Impairment of vision without detectable organic lesion of the eye.
Amblyopy
Weakness of sight (without opacity of the cornea or of the interior of the eye).
Amebiasis (amoebiasis)
A protozoan infection, especially by Entamoeba histolytica, which occurs worldwide in areas of poor sanitation. Typically such infections occur in the large intestine, rarely in the liver.
Amebicidal
Kills amebae.
Amenorrhea
Absence, discontinuation or abnormal stoppage of the menstrual periods. In primary amenorrhea menses have not begun by age 16, while secondary amenorrhea is slow reinitiation of menstruation from such causes as pregnancy, illness or dieting.
Analeptic
A drug that acts as a restorative, such as caffeine and amphetamine.
Analgesic
Alleviates pain without causing loss of consciousness.
Anaphrodisiac
Inhibits or decreases sexual desire.
Anaphylactic shock
A serious, often life-threatening allergic reaction that is characterised by low blood pressure, shock, and difficult breathing (see Allergy).
Anaphylaxis
Hypersensitivity from sensitization following prior contact with a causative agent. In immunology, an inflammatory reaction involving release of histamine and histamine-like substances, causing immune responses, and resulting in an acute allergic reaction with shortness of breath, rash, wheezing, and hypotension (also see Allergy).
Anasarca
Generalized massive edema; subcutaneous accumulation of serum, causing a soft, pale, inelastic swelling of the skin.
Androgens
Primarily male steroid hormones, produced in the adrenal glands and (in women) the ovaries.
Anemia (anaemia)
Abnormally low number of red blood cells or amount of hemoglobin in the blood. The lowered oxygen-transporting capacity results in fatigue, paleness, palpitations, and shortness of breath. Causes are varied (for example, bleeding, sickle cell anemia, iron deficiency, bone marrow diseases).
Anesthetic (anaesthetic)
Causes unconsciousness or a loss of general or local sensation.
Angina
Chest pain due to inadequate oxygen supply to heart muscle.
Angina pectoris
Sudden pain in the chest or arms brought on by lack of oxygen supply to the heart muscle. Generally refers to a chronic heart condition of this nature.
Anodyne
Externally-applied material that relieves pain or discomfort.
Anorexia
Uncontrolled lack or loss of appetite for food.
Anorexia nervosa
An eating disorder; individuals with this disease often believe they are overweight even when grossly underweight.
Anorexiant (anorectic, anorexiac)
A drug or substance that leads to anorexia or diminished appetite; an appetite suppressant.
Antacid
Counters or neutralises excess acidity, usually of the stomach.
Antarthritic
Counteracts or alleviates gout (cf. Antiarthritic; gout is (like arthritis) an inflammation of joints, but is specifically caused by deposits of urates in and around the joint).
Anthelmintic (anthelminthic)
Destroys and (or) expels internal parasitic worms from gut of animals and humans (see Vermifuge).
Anthrax
An infectious highly communicable disease caused by the bacterium Bacillus anthracis; symptoms include external ulcerating nodules and lesions in the lungs.
Antiacid
Counteracts or neutralises acidity.
Antiandrogen
An agent that interferes with the activity of male sex hormones.
Antiaphonic
Alleviates voice problems such as laryngitis.
Antiarrhythmic
An agent that prevents or alleviates cardiac arrhythmia (see Arrhythmia).
Antiarthritic
Alleviates arthritis (cf. Antarthritic).
Antiasthmatic
Alleviates spasm of asthma.
Antiatherogenic
Counteracts atherogenesis (the formation of lipid deposits in the arteries, which leads to atherosclerosis; see Antiatherosclerotic).
Antiatherosclerotic
Counteracts atherosclerosis (progressive narrowing and hardening of the arteries).
Antibacterial
Destroys bacteria or suppresses their growth or reproduction.
Antibilious
Alleviates or prevents excess bile.
Antibiotic
Chemical substance produced by a microorganism which inhibits growth of or kills other microorganisms.
Antibiotic resistance (drug resistance)
Acquired ability of bacteria and other microorganisms to withstand an antibiotic to which they were once susceptible.
Antibodies
Specialized proteins produced by white blood cells that circulate in the blood, attaching to and neutralizing foreign proteins, microorganisms or toxins.
Anticarcinogen
A chemical that counteracts the effect of a cancer-causing agent.
Anticatarrhal
Efficacious against catarrh reduces or stops production of mucus.
Anticholesterolemic
Reduces or prevents the build up of cholesterol in arteries.
Anticholinergic
An agent that blocks the parasympathetic nerves. This affects induction of spasms and cramps of the intestinal tracts and related ducts (see Parasympathetic nervous system).
Anticoagulant
Prevents or slows blood clotting, or removes blood clots.
Anticonvulsant
An agent that prevents or relieves convulsions.
Antidepressant
Alleviates depression.
Antidermatosic
Treats skin problems.
Antidiabetic
Prevents or alleviates diabetes.
Antidiuretic
Suppresses rate of urine formation.
Antidote
Counteracts poison.
Antiedemic
Counteracts edema.
Antiemetic (antinauseant)
Prevents or alleviates nausea and vomiting, for example during treatment with chemotherapy or radiotherapy.
Antifebrile
Alleviates fever (see Febrifuge).
Antiflatulent
Reduces intestinal gas (See carminative).
Antifungal
Effective against fungal infections.
Antigen
A substance, generally a protein, which induces counteractive antibodies.
Antigonadotropic
Inhibits functions of reproductive organs.
Antihelmintic (antihelminthic)
Counteracts parasitic worms, especially of the intestinal tract.
Antihemorrhagic (antihaemorrhagic)
Reduces or stops bleeding.
Antihemorrhoidal (antihaemorrhoidal)
Reduces inflammation of hemorrhoids.
Antihepatotoxic
Counteracting liver toxins.
Antihistamines (synonym of antihistamine as adjective & noun: antihistaminic)
Drugs that counteract the actions of histamine released during an allergic reaction. Antihistamines do not stop the formation of histamine nor stop the allergic reaction, but protect tissues from some of its effects, although often causing side effects (for example: mouth dryness, sleepiness, occasionally urine retention in males and fast heart rate); (see Allergy).
Antihydropic
Effective against dropsy.
Antihydrotic
Reduces perspiration.
Antihypertensive
Reduces high blood pressure.
Antihypertonic
Counteracts hypertonia.
Antihysteric
Alleviates hysteria.
Anti-infective
Inhibits spread of or kills infective agents.
Anti-inflammatory
Alleviates inflammation.
Antilithic
An agent preventing the formation of calculi (stones), especially uric-acid calculi, in the kidneys and other parts of the urinary system.
Antimicrobial
Kills microorganisms or suppresses their growth.
Antimitogenic
The reverse of mitogenic.
Antimitotic
A drug for inhibiting or preventing mitosis (cell division). The term is often used for compounds such as colchicine that cause metaphase arrest. Many antitumor drugs are antimitotic, blocking cell proliferation.
Antimycotic
Suppresses the growth of fungi.
Antineoplastic
Inhibits tumors.
Antineuralgic
Counters neuralgia.
Antiodontalgic
Counters toothache.
Antioxidant
Prevents or delays deterioration by action of oxygen in the air. Chemically, oxidation consists of an increase of positive charges on an atom or the loss of negative charges. Most biological oxidations are accomplished by the removal of a pair of hydrogen atoms (dehydrogenation) from a molecule. At the cellular level, oxidative reactions produce energy; however, free radicals and other oxidizing agents can damage membranes and other cell components and interfere with regulatory systems. Antioxidants such as vitamins C and E are able to counteract the damage from oxidation from oxygen-based free radicals. Beta carotene (the precursor of vitamin A) is an antioxidant said to protect cells against oxidation damage that can lead to cancer.
Antipellagral
Counters pellagra.
Antiperiodic
Prevents return of recurring disease, for example of intermittent fever.
Antiphlogistic
Counteracts inflammation and fever.
Antiplaque
Counteracts buildup of plaque on teeth.
Antipruritic
Alleviates or prevents itching of the skin.
Antipyretic
Alleviates fever (see Febrifuge).
Antirheumatic
Reduces rheumatism.
Antiscorbutic
Counteracts scurvy by providing vitamin C.
Antiscrophulatic (antiscrofulatic)
Treats scrofula.
Antiseptic
Inhibits growth and development of microorganisms.
Antispasmodic
Relieves muscular spasms and cramps.
Antisyphilitic
Efficacious against syphilis; a medicine used against syphilis.
Antithyrotropic
Inhibits thyroid function.
Antitumor (antitumour)
Counteracts tumor formation.
Antitussive
Relieves or suppresses cough (compare Expectorant).
Antiveratrinic
Acts against veratrine [a poisonous alkaloid mixture obtained from the root of hellebore (Veratrum) and from sabadilla (Schoenocaulon officinalis) seeds, sometimes used externally as a counterirritant to treat neuralgia and rheumatism, and also as an insecticide].
Antiviral
Alleviates or prevents virus diseases.
Anuria
The complete suppression of urinary secretion by the kidneys.
Aperient
A gentle laxative.
Aperitive
Stimulates the appetite.
Aphonia
Inability to produce speech sounds, often caused by disease of the vocal structures.
Aphrodisiac
Increases libido, i.e., desire for sex.
Aphtha
See Thrush.
Apoplexy
Sudden loss or reduction of consciousness and voluntary motion, due to rupture or obstruction of an artery in the brain.
Aposteme
An abscess; a swelling filled with pus. (Corrupted as "imposthume.")
Appetizer
Improves appetite.
Aromatherapy
Utilizes the presumed medicinal properties of essential oils extracted from plants. Treatments may be administered through inhalation, external application (e.g., bath, massage, compress, or topically), or (untypically) by ingestion. Essential oils may be antibacterial, antiviral, antispasmodic, and may have such varied pharmacological actions as widening or narrowing blood vessels, or acting on the adrenals, ovaries, and the thyroid. The potential for toxicity exists.
Aromatic
1. Chemically, molecules with one or more benzene rings.
2. Plant constituents which vaporize and can be smelled.
3. An agent added to a medicine to give it aroma or flavor.
Arrhythmia
Abnormal rhythm, generally referring to heart. The heartbeats may be too slow, too rapid, irregular, or too early. Rapid arrhythmias (>100 beats/minute) are tachycardias. Slow arrhythmias (<60 beats/ minute) are bradycardias. Irregular heart rhythms are called fibrillations (e.g. atrial fibrillation).
Arteriosclerosis ("hardening of the arteries")
A chronic disease marked by abnormal thickening and hardening of the walls of the arteries.
Arthralgia
Pain in joints.
Arthritis
Inflammation of a joint (symptoms may include stiffness, warmth, swelling, redness, and pain). There are over 100 types of arthritis. Osteoarthritis (degenerative arthritis) is a type caused by inflammation, breakdown, and eventual loss of the cartilage of the joints.
Arthrogryposis
A congenital disease in which those affected are born with stiff joints and weak muscles.
Arthrosis
A disease of a joint.
Ascariasis
Infection by the nematode Ascaris lumbricoides (the "common roundworm"). Adult worms are 15-40 cm in length and live in the small intestine. Infection occurs after ingesting eggs in contaminated food or more commonly, by transmission to the mouth by the hands after contact with contaminated soil.
Ascaridial
Removes roundworms (nematode worms of the family Ascaridae), especially the common roundworm, Acaris lumbricoides.
Ascites
Abnormal accumulation of serous fluid in the abdominal cavity. This most commonly results from trauma.
Aseptic
Refers to absence of microorganisms.
Astringent
Causes contraction, usually locally after topical application. By reducing the size of liquid-carrying channels, or reducing the area of injuries, astringents can reduce the flow of secretions and discharges such as blood, mucus and diarrhea.
Ataractic
An agent that can produce sedation without profound drowsiness; tranquillizer.
Ataxia
Muscular incoordination, irregularity of muscular action.
Atheroma
1. An encysted tumor containing curdy matter.
2. A disease characterised by thickening and fatty degeneration of the inner coat of the arteries.
Atonic
1. Characterized by atony, or want of vital energy or strength.
2. A remedy capable of alleviating excitement or irritation.
Autonomic nervous system
A component of the nervous system regulating key functions including the activity of the cardiac (heart), muscle, smooth muscles (e.g., of the gut), and glands. It has two divisions: the sympathetic nervous system that accelerates the heart rate, constricts blood vessels, and raises blood pressure; and the parasympathetic nervous system which slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles.
Avicidal
Kills birds.
Azotemia
Abnormally high level of nitrogen-type wastes in the bloodstream, associated with kidney dysfunction (compare Uremia).