Abortifacient: A substance that induces abortion.
Abscess: A localized collection of pus and liquefied tissue in a cavity.
Acetylcholine: One of the chemicals that transmit impulses between nerves and between nerves and muscle cells.
Acrid: Pungent and biting, causing irritation.
Acute: Having a rapid onset, severe symptoms, and a short course; not chronic.
Adaptogen: A substance that is safe, increases resistance to stress, and has a balancing effect on body functions.
Adjuvant: A substance that enhances the effect of a medicinal agent or increases the antigenicity of a cancer cell.
Adrenaline: A hormone secreted by the adrenal gland that produces the “fight-or-flight” response. Also called epinephrine.
Aldosterone: A hormone secreted by the adrenal gland that causes the retention of sodium and water.
Alkaloids: Naturally occurring amines (nitrogen-containing compounds) arising from heterocyclic and often complex structures that display pharmacological activity. The names of alkaloids usually end in -ine.
Allopathy: The conventional method of medicine that combats disease by using substances and techniques specifically targeting the disease.
Alterative: A substance that produces a balancing effect on a particular body function.
Amebiasis: An intestinal infection characterized by severe diarrhea caused by the parasite Entamoeba histolytica.
Amino acids: A group of nitrogen-containing chemical compounds that form the basic structural units of proteins.
Analgesic: A substance that reduces the sensation of pain.
Androgen: A hormone that stimulates male charateristics.
Anthelminthic: A substance that causes the elimination of intestinal worms.
Anthocyanidin: A particular class of flavonoids that gives plants, fruits, and flowers colors ranging from red to blue.
Antibody: A protein manufactured by the body that binds to antigens to neutralize, inhibit, or destroy it.
Antidote: A substance that neutralizes or counteracts the effects of a poison.
Antigen: A substance that when introduced into the body causes the formation of antibodies against it.
Antihypertensive: Having a blood-pressure-lowering effect.
Antioxidant: A compound that prevents free-radical or oxidative damage.
Aphrodisiac: A substance that increases sexual desire.
Artery: A blood vessel that carries oxygen-rich blood away from the heart.
Astringent: An agent that causes the contraction of tissue.
Atherosclerosis: A process in which fatty substances (cholesterol and triglycerides) are deposited in the walls of medium to large arteries, eventually leading to their blockage.
Atopy: A predisposition to various allergic conditions, including eczema and asthma.
Autoimmunity: A process in which antibodies develop against the body’s own tissues.
Balm: A soothing or healing medicine applied to the skin.
Basal metabolic rate: The rate of metabolism when the body is at rest.
Basophil: A type of white blood cell involved in allergic reactions.
Benign: Term describing a mild disorder that is usually not fatal.
Beta-carotene: Provitamin A; a plant carotene that can be converted to two vitamin A molecules.
Beta cells: The cells in the pancreas that manufacture insulin.
Bilirubin: The breakdown product of the hemoglobin molecule of red blood cells.
Biopsy: A diagnostic test in which tissue or cells are removed from the body for examination under a microscope.
Bleeding time: The time required for the cessation of bleeding from a small skin puncture as a result of platelet disintegration and blood vessel constriction. Ranges from 1 to 4 minutes.
Blood-brain barrier: A barrier that prevents the passage of materials from the blood to the brain.
Blood pressure: The force exerted by blood as it presses against and attempts to stretch blood vessels.
Bromelain: The protein-digesting enzyme found in pineapple.
Bursa: A sac or pouch containing a special fluid that lubricates joints.
Bursitis: Inflammation of a bursa.
Calorie: A unit of heat. A nutritional calorie is the amount of heat necessary to raise 1 kilogram of water 1°C.
Candida albicans: A yeast common to the intestinal tract.
Candidiasis: A complex medical syndrome produced by a chronic overgrowth of the yeast Candida albicans.
Carbohydrates: Sugars and starches.
Carcinogen: Any agent or substance capable of causing cancer.
Carcinogenesis: The development of cancer caused by the actions of certain chemicals, viruses, and unknown factors on primarily normal cells.
Cardiac output: The volume of blood pumped from the heart in one minute.
Cardiopulmonary: Pertaining to the heart and lungs.
Cardiotonic: A compound that tones and strengthens the heart.
Carminative: A substance that promotes the elimination of intestinal gas.
Carotene: A fat-soluble plant pigment, some of which can be converted into vitamin A by the body.
Cartilage: A type of connective tissue that acts as a shock absorber at a joint interface.
Cathartic: A substance that stimulates the movement of the bowels; more powerful than a laxative.
Cholagogue: A compound that stimulates the contraction of the gallbladder.
Cholecystitis: Inflammation of the gallbladder.
Cholelithiasis: Gallstones.
Choleretic: A compound that promotes the flow of bile.
Cholestasis: The stagnation of bile within the liver.
Cholinergic: Pertaining to the parasympathetic portion of the autonomic nervous system and the release of acetylcholine as a transmitter substance.
Chronic: Long-term or frequently recurring.
Cirrhosis: A severe disease of the liver characterized by the replacement of liver cells with scar tissue.
Coenzyme: A necessary nonprotein component of an enzyme, usually a vitamin or mineral.
Cold sore: A small skin blister anywhere around the mouth caused by the herpesvirus.
Colic: Severe, spasmodic pain that occurs in waves of increasing intensity, reaches a peak, then abates for a short time before returning.
Colitis: Inflammation of the colon that is usually associated with diarrhea containing blood and mucus.
Collagen: The protein that is the main component of connective tissue.
Compress: A linen or cotton pad applied under pressure to an area of skin and held in place.
Congestive heart failure: A chronic disease that results when the heart is not capable of supplying the oxygen demands of the body.
Connective tissue: The type of tissue that performs the function of providing support, structure, and cellular cement to the body.
Contagious: Transferable from one person to another by social contact, such as sharing the home or workplace.
Coronary artery disease: A condition in which the heart receives an inadequate blood and oxygen supply, owing to atherosclerosis.
Corticosteroid drugs: A group of drugs similar to the natural corticosteroid hormones that are used predominantly in the treatment of inflammation and to suppress the immune system.
Corticosteroid hormones: A group of hormones produced by the adrenal glands that control the body’s use of nutrients and the excretion of salt and water in the urine.
Cushing’s syndrome: A condition caused by a hypersecretion of cortisone and characterized by spindly legs, “moon face,” “buffalo hump,” abdominal obesity, flushed facial skin, and poor wound healing.
Cyst: An abnormal lump or swelling filled with fluid or semisolid material in any body organ or tissue.
Cystitis: Inflammation of the inner lining of the bladder. It is is usually caused by a bacterial infection.
Decoction: A tea prepared by boiling a botanical in water for a specified period of time, followed by straining or filtering.
Dehydration: Excessive loss of water from the body.
Dementia: Senility; loss of mental function.
Demineralization: Loss of minerals from bones.
Demulcent: A substance soothing to irritated mucous membranes.
Dermatitis: Inflammation of the skin, sometimes due to allergy.
Diastolic: The lower number in a blood pressure reading; the measure of the pressure in the arteries during the relaxation phase of the heartbeat.
Disaccharide: A sugar composed of two monosaccharide units.
Diuretic: A substance that increases urination.
Diverticuli: Saclike outpouchings of the wall of the colon.
Double-blind study: A way of controlling against experimental bias by ensuring that neither the researcher nor the subject knows when an active agent or a placebo is being used.
Douche: Introduction of water and/or a cleansing agent into the vagina with the aid of a bag with a tube and nozzle attached.
Dysfunction: Abnormal function.
Dysplasia: An abnormality of growth.
Edema: Accumulation of fluid in tissues (swelling).
Eicosapentaenoic acid (EPA): A fatty acid found primarily in cold-water fish.
Electroencephalogram: A machine that measures and records brain waves.
Elimination diet: A diet that eliminates allergenic foods.
Emulsify: To disperse large fat globules into smaller, uniformally distributed particles.
Encephalitis: Inflammation of the brain, usually due to viral infection.
Endometrium: The mucous membrane lining of the uterus.
Enteric-coated: A tablet or capsule that is coated to ensure that it does not dissolve in the stomach so it can reach the intestinal tract.
Enzyme: An organic catalyst that speeds chemical reactions.
Epidemiology: The study of the occurrence and distribution of diseases in human populations.
Epinephrine: See Adrenaline.
Epithelium: The cells that cover the entire surface of the body and that line most of the internal organs.
Epstein-Barr virus: The virus that causes infectious mononucleosis and is associated with Burkitt’s lymphoma and nasopharyngeal cancer.
Essential fatty acid: A fatty acid that the body cannot manufacture; examples are linoleic acid and linolenic acid.
Essential oil: Also known as volatile oil, ethereal oil, or essence. Usually a complex mixture of a wide variety of organic compounds (alcohols, ketones, phenols, acids, ethers, esters, aldehydes, oxides, etc.) that evaporate when exposed to air. Generally represents the odoriferous principles of plants.
Estrogen: A hormone that stimulates female characteristics.
Excretion: The process of elimination of waste products from a cell, a tissue, or the entire body.
Extracellular space: The space outside the cell, composed of fluid.
Extract: A concentrated form of a natural product that is obtained by treating a crude material containing a certain substance with a solvent and then removing the solvent completely or partially from the preparation. The most common are fluid extracts, solid extracts, powdered extracts, tinctures, and native extracts.
Exudate: Escaping fluid or semifluid material that oozes from a space that may contain serum, pus, and cellular debris.
Faruncle: Another name for a boil that involves a hair follicle.
Fibrin: A white insoluble protein formed by the clotting of blood that is the starting point for wound repair and scar formation.
Fibrinolysis: The dissolution of fibrin or a blood clot by the action of enzymes that convert insoluble fibrin into soluble particles.
Flavonoid: A generic term for a group of flavone-containing compounds that are found widely in nature. They include many of the compounds that account for plant pigments (anthocyanins, anthoxanthins, apigenins, flavones, flavonols, bioflavonols, etc.). They exert a wide variety of physiological effects in the human body.
Fluid extract: Typically a hydroalcoholic solution with a strength of 1 part solvent to 1 part herb. The alcohol content varies with each product. In essence, a concentrated tincture.
Free radical: A highly reactive molecule characterized by an unpaired electron that can bind to and destroy cellular compounds.
Gerontology: The study of aging.
Giardiasis: An infection of the small intestine caused by the protozoan (single-celled organism) Giardia lamblia.
Gingivitis: Inflammation of the gums.
Glaucoma: A condition in which the pressure of the fluid in the eye is so high that it causes damage.
Glucose: A monosaccharide found in the blood that is one of the body’s primary energy sources.
Gluten: One of the proteins in wheat and certain other grains that gives dough its tough, elastic character.
Glycoside: A sugar-containing compound composed of a glycone (sugar component) and an aglycone (non-sugar-containing component) that can be cleaved on hydrolysis. The glycone portion may be glucose, rhamnose, xylose, fructose, arabinose, or any other sugar. The aglycone portion can be any kind of compound, e.g., a sterol, triterpene, anthraquinone, hydroquinone, tannin, carotenoid, or anthocyanidin.
Goblet cell: A goblet-shaped cell that secretes mucus.
Ground substance: The thick, gel-like material in which the cells, fibers, and blood capillaries of cartilage, bone, and connective tissue are embedded.
Helper T cell: A lymphocytes that helps the immune response.
Hematocrit: The expression of the percentage of blood occupied by blood cells.
Hemorrhoid: A distended vein in the lining of the anus.
Hepatic: Pertaining to the liver
Hepatomegaly: Enlargement of the liver.
Holistic medicine: A form of therapy aimed at treating the whole person, not just the part or parts in which symptoms occur.
Hormone: A secretion of an endocrine gland that controls and regulates body functions.
Hyperglycemia: High blood sugar.
Hyperlipidemia: High levels of of cholesterol and triglycerides in the blood.
Hypersecretion: Excessive secretion.
Hypertension: High blood pressure.
Hypochlorhydria: Insufficient gastric acid output.
Hypoglycemia: Low blood sugar.
Hypolipidemia: Low levels of cholesterol and triglycerides in the blood.
Hypotension: Low blood pressure.
Hypoxia: An inadequate suppy of oxygen.
Iatrogenic: Literally “physician produced,” the term can be applied to any medical condition, disease, or other adverse occurrence that results from medical treatment.
Idiopathic: Of unknown cause.
Immunoglobulin: Antibody.
Incidence: The number of new cases of a disease occurring during a given period (usually years) in a defined population.
Incontinence: The inability to control urination or defecation.
Infarction: Death of a localized area of tissue due to lack of oxygen supply.
Infusion: A tea produced by steeping a botanical in hot water.
Insulin: A hormone secreted by the pancreas that lowers blood sugar levels.
Interferon: A potent immune-enhancing substance that is produced by the body’s cells to fight off viral infection and cancer.
In vitro: Outside a living body and in an artificial environment.
In vivo: In a living body of an animal or plant.
Jaundice: A condition caused by elevation of bilirubin in the body and characterized by yellowing of the skin.
Keratin: An insoluble protein found in hair, skin, and nails.
Lactase: An enzyme that breaks down lactose into the monosaccharides glucose and galactose.
Lactose: One of the sugars present in milk. It is a disaccharide.
Laxative: A substance that promotes the evacuation of the bowels.
LD50: The dosage that will kill 50 percent of the animals taking a substance.
Lesion: Any localized, abnormal change in tissue formation.
Lethargy: A feeling of tiredness, drowsiness, or lack of energy.
Leukocyte: White blood cell.
Leukotriene: An inflammatory compound produced when oxygen interacts with polyunsaturated fatty acids.
Lipids: Fats, phospholipids, steroids, and prostaglandins.
Lipotropic: Promoting the flow of lipids to and from the liver.
Lymph: Fluid contained in lymphatic vessels that flows through the lymphatic system to be returned to the blood.
Lymphocyte: A type of white blood cell found primarily in lymph nodes.
Malabsorption: Impaired absorption of nutrients, most often due to diarrhea.
Malaise: A vague feeling of being sick or of physical discomfort.
Malignant: A term used to describe a condition that tends to worsen and eventually causes death.
Manipulation: As a therapy, the skillful use of the hands to move a part of the body or a specific joint or muscle.
Mast cell: A cell found in many tissues of the body that contributes greatly to allergic and inflammatory processes by secreting histamine and other inflammatory particles.
Menorrhagia: Excessive loss of blood during menstrual periods.
Menstrum: A solvent used for extraction, e.g., water, alcohol, acetone.
Metabolism: A collective term for all the chemical processes that take place in the body.
Metabolite: A product of a chemical reaction.
Metalloenzyme: An enzyme that contains a metal at its active site.
Microbe: A popular term for microorganism.
Microflora: The microbial inhabitants of a particular region, e.g., the colon.
Mites: Eight-legged animals less than 
inch (1.2 mm) long that are similar to tiny spiders.
Molecule: The smallest complete unit of a substance that can exist independently and still retain the characteristic properties of the substance.
Monoclonal antibody: A genetically engineered antibody specific to one particular antigen.
Monosaccharide: A simple, one-unit sugar such as fructose or glucose.
Mortality rate: The number of deaths per 100,000 population per year.
Mucosa: Another term for mucous membrane.
Mucous membrane: The soft pink tissue that lines most of the body’s cavities and tubes, including the respiratory tract, gastrointestinal tract, genitourinary tract, and eyelids. The mucous membranes secrete mucus.
Mucus: The slick, slimy fluid secreted by the mucous membranes that acts as a lubricant and mechanical protector of the mucous membranes.
Mycotoxin: A toxin produced by yeast or a fungus.
Myelin sheath: A white fatty substance that surrounds nerve cells to aid in nerve impulse transmission.
Neoplasia: A tumor formation characterized by a progressive, abnormal replication of cells.
Neurofibrillary tangle: A cluster of degenerated nerves.
Neurotransmitter: A substance that modifies or transmits nerve impulses.
Night blindness: The inability to see well in dim light or at night.
Nocturia: Disturbance of a person’s sleep at night by the need to pass urine.
Oleoresin: Generally, a mixture of resins and volatile oils either occuring naturally or made by extracting the oily and resinous materials from botanicals with organic solvents (e.g., hexane, acetone, ether, alcohol). The solvent is then removed under vacuum, leaving behind a viscous, semisolid extract that is the oleoresin. Examples of prepared oleoresins are paprika, ginger, and capsicum.
Oligoantigenic diet: See Elimination diet.
Otitis media: Acute infection of the middle ear.
Pancreatin: An extract of pork pancreas.
Papain: The protein-digesting enzyme in papaya.
Parkinson’s disease: A slowly progressive, degenerative nervous system disease characterized by resting tremor, “pill rolling” by the fingers, a masklike facial expression, a shuffling gait, and muscle rigidity and weakness.
Pathogen: Any agent, particularly a microorganism, that causes disease.
Pathogenesis: The process by which a disease originates and develops, particularly cellular and physiological processes.
Peristalsis: Successive muscular contractions of the intestines that move food through the intestinal tract.
Physiology: The study of the functioning of the body, including the physical and chemical processes of its cells, tissues, organs, and systems.
Physostigmine: A drug that blocks the breakdown of acetylcholine.
Phytoestrogen: A plant compound that exerts an estrogenic effect.
Placebo: An inert or inactive substance used to test the efficacy of another substance.
Polysaccharide: A molecule composed of many sugar molecules linked together.
Powdered extract: A solid extract that has been dried as a powder.
Prostaglandin: A hormonelike compound manufactured from essential fatty acids.
Psychosomatic: Pertaining to the relationship between the mind and body. Commonly used to refer to physiological disorders thought to be caused entirely or partly by psychological factors.
Putrefaction: The process of breaking down protein compounds by rotting.
RDA: Recommended Dietary Allowance.
Resin: A complex oxidative product of a terpene that occurs naturally as a plant exudate or is prepared by alcohol extraction of a botanical that contains a resinous principle.
Saccharide: A sugar molecule.
Saponin: A nonnitrogenous glycoside, typically with sterol or triterpene as the aglycone, that possesses the property of foaming, or making suds, when strongly agitated in aqueous solution.
Satiety: A feeling of fullness or gratification.
Saturated fat: A fat whose carbon atoms are bonded to the maximum number of hydrogen atoms; found in animal products such as meat, milk, milk products, and eggs.
Sclerosis: The process of hardening or scarring.
Senile dementia: Mental deterioration associated with aging.
Slow-reacting substance of anaphylaxis (SRSA): A potent allergic mediator produced and released by mast cells.
Solid extract: An extract from which all of the residual solvent or liquid has been removed.
Submucosa: The tissue just below the mucous membrane.
Suppressor T cell: A lymphocyte controlled by the thymus gland that suppresses the immune response.
Syndrome: A group of signs and symptoms that occur together in a pattern characteristic of a particular disease or abnormal condition.
T cell: A lymphocyte that is under the control of the thymus gland.
Tincture: An alcoholic or hydroalcoholic solutions that usually contains the active principles of a botanical in a low concentration. It is usually prepared by maceration, percolation, or dilution of its corresponding fluid or native extracts. The strength of a tincture is typically 1 to 10 or 1 to 5; the alcohol content varies.
Tonic: A substance that exerts a gentle strengthening effect on the body.
Trans-fatty acid: A detrimental type of fat found in margarine, dairy products, and many processed foods.
Uremia: The retention of urine by the body and the presence of high levels of urine components in the blood.
Urinalysis: The analysis of urine.
Urticaria: Hives.
Vasoconstriction: The constriction of blood vessels.
Vasodilation: The dilation of blood vessels.
Vitamin: An essential compound necessary to act as a catalyst in normal processes of the body.
Western diet: A diet characteristic of Western societies, i.e., a diet high in fat, refined carbohydrates, and processed foods and low in dietary fiber.
Wheal: The characteristic lesion in hives; a small welt.