Alopecia areata (al-uh-PEE-shuh air-ee-AH-tuh) is a condition that causes hair loss on the scalp and sometimes elsewhere on the body.

More to Know

Both boys and girls can get alopecia areata, which can begin at any age. It is believed to happen when the body's immune system, which normally fights infections, attacks the hair follicles (the area of skin hair grows from) as if they were a threat. This disrupts hair growth.

Alopecia areata often starts as one or more round, smooth bald patches on the scalp. While uncommon, it is possible for all the hair on the head to fall out. Often, hair grows back within several months, even without treatment. Hair may grow in fine or white at first, but usually returns to its original texture and color with time.

People with alopecia areata may lose and grow back their hair more than once, either in the same patches as before or in different patches. Almost always the hair grows back; very rarely, the hair loss is permanent.

Alopecia areata also can affect the fingernails and toenails. White spots may appear on the nails; the nails may feel pitted, grooved, or rough; or they may be thin and split easily.

Keep in Mind

Treatment for alopecia areata is not usually necessary, but medicine that is applied to the scalp may help hair grow back faster. Injections and oral medications are sometimes used instead. None of the treatments cure alopecia areata. Hair loss can still occur again after treatment.

The hair loss that comes with alopecia areata can be upsetting, but it is not contagious and usually occurs in people who are otherwise healthy.

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