» Allergy
a hypersensitivity to a specific substance (such as a food, pollen, dust, etc.) or condition (such as heat or cold) which in similar amounts is harmless to most people. Allergies are manifested in a physiological disorder, such as sneezing or itching.

» Antibiotic
a drug with the ability to kill bacteria.

» Antibody
an immunoglobulin that binds specifically to a given antigen.

» Anticoagulant
any agent used to prevent the formation of blood clots.

» Antigen
a substance that reacts with antibodies or memory T cells to cause an immune reaction. An antigen that binds with a specific antibody or T cell can cause allergies.

»Anti-Oxidant
an enzyme or other organic molecule that can counteract the damaging effects of oxygen in tissues caused by free radicals and thus intimately involved in the prevention of cellular damage -- the common pathway for cancer, aging, and a variety of diseases.

» Antiseptic
something that discourages the growth of microorganisms.

» Antihistimine
a substance capable of reducing inflammation, swelling and other effects often experienced as an allergic reaction.

» Atopic
hereditary tendency to experience immediate allergic reactions because of the presence of an antibody in the skin.

» Atopic Dermatitis
eczema