Alopecia areata is an autoimmune disorder that causes your hair to come out, often in clumps the size and shape of a quarter. The amount of hair loss is different in everyone. Some people lose it only in a few spots. Others lose a lot. Sometimes, hair grows back but falls out again later. In others, hair grows back for good.
There are different types of this condition. Alopecia areata is most common in its main form, but there are other, more rare types:
- Alopecia areata totalis means you’ve lost all the hair on your head.
- Alopecia areata universalis is the loss of hair over your entire body.
- Diffuse alopecia areata is a sudden thinning of your hair rather than lost patches.
- Ophiasis alopecia areata causes hair loss in a band shape around the sides and back of your head.