Alopecia Areata: A disease that causes sudden smooth,
circular patches of hair loss. It is thought that it is caused by the body
forming antibodies against some hair follicles. It can result from such factors
as stress and genetics.
Alopecia Totalis: A condition that results in no hair on
the scalp. It may begin as Alopecia areata or some other cause.
Alopecia Universalis: A condition that results in no hair
on any part of the body; this includes eyelashes, eyebrows, and scalp hair. It
may develop as alopecia areata or result from another cause.
Amino Acids: The building blocks of protein. A deficiency
of amino acids may adversely affect hair growth.
Amortization: The process of converting one enzyme to
another, such as testosterone to dihydrotestosterone.
Anagen: The growing phase of hair, usually lasting between
two and six years.
Anagen Effluvium: Loss of hair that is supposed to be in
the anagen or growing phase. This is the type of hair loss that is associated
with chemotherapy or radiation treatment.
Androgen: general term referring to any male hormone. The
major androgen is testosterone.
Androgenetic Alopecia: Hair loss resulting from a genetic
predisposition to effects of dihydrotestosterone (DHT) on the hair follicles.
Also termed female pattern baldness and male pattern baldness, hereditary
alopecia, and common baldness.
Antiandrogen: An agent that blocks the action of androgens
by preventing their attachment to receptor cells, interfering with their
metabolism, or decreasing their production in the body.
Aromatase: An enzyme (actually an enzyme complex) involved
in the production of estrogen that acts by catalyzing the conversion of
testosterone (an androgen) to estradiol (an estrogen). Aromatase is located in
estrogen-producing cells in the adrenal glands, ovaries, placenta, testicles,
adipose (fat) tissue, and brain.
Autograft: A graft taken from your own body. Azelaic Acid:
Azelaic acid (like Retin-A) is more commonly used in the treatment of acne and
other skin conditions. It inhibits the activity of the enzyme 5
alpha-reductase, involved in the conversion of testosterone to DHT.