Androgenetic alopecia (male pattern hair loss) is the most common type of hair loss in men. The condition is characterized by the progressive loss of terminal hairs on the scalp in a characteristic distribution. The anterior scalp, mid scalp, temporal scalp, and vertex of the scalp are typical sites of involvement.
Androgenetic alopecia is considered an androgen-dependent trait that requires a genetic predisposition. The interaction of these factors and other mechanisms that remain to be elucidated contributes to follicular miniaturization (the transition of larger, terminal hair fibers to small vellus hair fibers) in susceptible scalp areas.