Hair Loss Glossary

Aldactone: Brand name for spironolactone, a prescription high blood pressure medication that is also prescribed to treat women’s hair loss.

Alopecia: Loss of hair as a result of illness, functional disorder, or hereditary disposition. The medical term for hair loss.

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Drug-Induced Hair Loss

Medications are designed to treat a variety of health conditions, but sometimes they can have unwanted side effects. Certain drugs can contribute to excess hair growth, changes in hair color or texture, or hair loss. Drug-induced hair loss, like any other type of hair loss, can have a real effect on your self-esteem. The good news is that in most cases, it’s easily reversible once you stop taking the drug.

Read the Drug-Induced Hair Loss article > >

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.


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.

Anterior: Front



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.

Biopsy: Piece of tissue cut out for microscopic examination

Bonding: A term used to describe the simple act of gluing a hairpiece onto the scalp.

Catagen: The intermittent stage between the growing (anagen) and resting (telogen) phases of the hair’s growth cycle.

Chemotherapy: Chemical treatment, usually of cancers, using drugs that have high levels of toxicity, frequently causing temporary alopecia.

Club Hair: A hair that has stopped growing or is no longer in the anagen phase. It is anchored to the skin with its “club-like” root, but will eventually be pushed out and replaced by a growing hair.