Baldness is loss or lack of hair, usually from the top of the head. It may also occur on other parts of the body where hair grows. Baldness is usually part of the aging process. Some diseases and drugs may also cause baldness. Hair loss may be either temporary or permanent, depending on the cause.
Hereditary baldness is passed through the family.
It is most common in men, but sometimes occurs in women. Local hair loss is usually patchy and confined to certain areas. Alopecia universalis is a rare and severe form of baldness that results in permanent loss of all body hair, including eyebrows, eyelashes, and hair in the pubic area and armpits. The cause is unknown. Hair loss may also occur when all of the scalp hair enters a resting phase at the same time and then falls out.