Cause

Inherited hair loss
The most common cause of hair loss is genetics—you inherit the tendency to lose hair from either or both of your parents. This is called male-pattern hair loss or female-pattern hair loss. The medical term for this type of hair loss is androgenetic alopecia. In this type of hair loss, your genes affect how your hair grows. They trigger a sensitivity to a class of hormones called androgens, including testosterone, which causes hair follicles (which hair grows from) to shrink. Shrinking follicles produce thinner hair and eventually none at all. Men generally develop bald spots on the forehead area or on the top of the head, while women have an overall thinning of the hair throughout the scalp. About half of all people have inherited hair loss by about 50 years of age.