Alopecia is hair loss from the scalp. Alopecia is also known as male-pattern hair loss or balding in men, or female-pattern hair loss in women.
The most common cause of hair loss is androgenetic alopecia which is thinning of the hair caused by androgens (male hormones) in those who have inherited a genetic tendency towards balding.
Drug treatments for hereditary balding include the drugs finasteride and minoxidil.
Another cause of hair loss is alopecia areata. Alopecia areata is considered an autoimmune disease, in which the immune system, which is designed to protect the body from foreign invaders such as viruses and bacteria, mistakenly attacks the hair follicles, the tiny cup-shaped structures from which hairs grow. This can lead to hair loss on the scalp and elsewhere.