androgenetic alopecia

androgenetic alopecia n hereditary androgen-dependent hair loss that is associated with the shrinkage of hair follicles and the shortening of the anagen phase of hair growth and that is typically characterized by moderate to severe hair loss on the temples and crown in men and diffuse thinning on the crown in women see male-pattern baldness

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alopecia androgenetica, androgenic alopecia progressive, diffuse, symmetric loss of scalp hair. In men it may begin in the twenties or early thirties, with hair loss from the vertex and the frontoparietal regions; in some men it progresses to finally leave only a sparse peripheral rim of scalp hair. This is also called male pattern a. or baldness. In women it may begin later, with less severe hair loss in the front area of the scalp. This is also called female pattern a. or baldness. In affected areas, hair follicles produce finer and lighter terminal hairs until terminal hair production ceases; the phase called anagen becomes longer, while telogen becomes shorter. The etiology is unknown but may be a combination of genetic factors and increased response of hair follicles to androgens.

Androgenetic alopecia showing frontal and vertex thinning typical for men.