By the age of 35 two-thirds of American men will experience some degree of appreciable hair loss, and by the age of 50 approximately 85% of men have significantly thinning hair.
Approximately 25% of men who suffer with male pattern baldness begin the process before they reach the age of 21.
Male pattern baldness is responsible for the vast majority of male hair loss. More than 95% of male hair loss is due to male-pattern baldness, a genetic trait. The gene can come from either parent. In male pattern baldness, the main symptom is a receding hairline and hair loss at the crown of the head. Toward the end of the stages of male pattern baldness, the only hair remaining is in a horseshoe pattern around the base of the scalp.