Male pattern baldness is an inherited condition from either the mother or father’s side of the family. There is a common myth that inheritance is only from the mother’s side, but this is not the case.
It is estimated that 35 million men in the United States are affected by male pattern baldness or androgenetic alopecia. “Andro” refers to the androgens (testosterone, dihydrotestosterone) necessary to produce male-pattern baldness (MPB). “Genetic” refers to the inherited gene necessary for MPB to occur. In men who develop male pattern baldness the hair loss may begin any time after puberty.
In some men, initial male-pattern baldness may be delayed until the late 30’s or 40’s. It is generally found that men in their 20’s have a 20% incidence of male pattern baldness, a 30% incidence in their 30’s, a 40% incidence in their 40’s, etc.
The hair growth cycle is affected by the the percentage of hairs in the growth phase (anagen) and the duration of this growth phase, which equates to the length of hair. The longer hairs are in the resting state (telogen) they are more subject to loss with the daily trauma of combing and washing. The hair shafts in male pattern baldness become progressively smaller in diameter and length, with time.