What is alopecia areata (hair loss)?

Alopecia areata is a type of hair loss that affects millions of people worldwide. It is an autoimmune disease that causes patches of baldness to appear on the scalp, face and other parts of the body. This condition can cause brittle hair, which can lead to further hair loss if not treated properly. Alopecia areata is most common in young adults and children, but can affect anyone at any age. Knowing more about alopecia areata can help people recognize the signs and symptoms early so they can seek treatment right away.