Androgenetic hair loss
It should be kept in mind that even the presence of both, necessary genes and hormones, is not sufficient to cause androgenetic hair loss. The hair loss process also needs time, during which susceptible hair follicles will be exposed to male hormones. The time required for this kind of hair loss to take place varies from one individual to another. The development of male pattern baldness is dependent on a person’s genetic expression and the level of androgens in his or her blood.
Moreover, even when there is no predisposition to androgenetic hair loss, as people get older, some hairs randomly begin to shrink both in length and diameter. This process is called miniaturization. As a result, miniaturized hairs will be shed and actual follicular units decrease in number.