While there are other reasons why men lose their hair, including disease, medical treatments, and trauma, by far the most common reason is simple androgenic alopecia or male pattern baldness (MPB).
Most male hair loss is usually attributable to genetics and more specifically, to the conversion of the male hormone testosterone to DHT. DHT causes hair follicles to shrink and gradually disappear. The first sign of MPB is typically a receding hairline and thinning at the crown. Hair in these areas appears to be the most sensitive to DHT. As MPB progresses, the entire top of the scalp may go bald, leaving only a “horseshoe” of hair. For some men, even this remaining rim of hair will ultimately be lost.
The good news is that DHT-blocking drugs and laser therapies can slow or even stop MPB if it’s caught early enough.
