In general, alopecia areata is unpredictable. There is no way to tell when the hair will fall out, when it will grow back, how much will grow back, and how long the hair growth will last. Medical treatments such as corticosteroids and immunosuppressants are able to suppress the autoimmune response and give the body a better chance at growing and retaining hair.

People with more advanced forms of alopecia areata, such as Totalis, Universalis, Ophiasis, etc., tend to be more resistant to meaningful hair growth, but this does not mean that they cannot regrow hair. This lack of understanding underpins the need to fund biomedical research for alopecia areata.