How common is male pattern hair loss?
Male pattern hair loss affects at least 50% of men at some point in their lives, and possibly as many as 80% by the age of 70 years. It affects different populations at different rates, probably because of genetics. Up to half of male Caucasians will experience some degree of hair loss by age 50, while other population groups such as Japanese and Chinese men are far less affected. The severity of hair loss can be classified in several ways. Illustrated is the Norwood classification. The Norwood classification of male pattern alopecia. Image © 1998 Merck Sharpe & Dohme, with permission.
