Alopecia areata is an unpredictable autoimmune skin disease where your immune system attacks your healthy hair follicles, leading to hair loss. This condition can affect everyone differently, and there are three main types: patchy alopecia areata, alopecia totalis, and alopecia universalis. Patchy alopecia areata causes small, round, smooth patches of hair loss on any part of the body. Alopecia totalis results in complete hair loss on the scalp, often starting as patchy alopecia areata. Alopecia universalis is the rarest form and leads to hair loss across the entire body, including eyebrows, eyelashes, and other body hair. Hair loss can be mild or severe, and it may be temporary or permanent. Some people may experience hair regrowth, while others may not. The condition can develop at any age and may be triggered by factors like stress, trauma, or other illnesses. Treatments vary and may include medications to stop the immune system from attacking hair follicles and to stimulate new hair growth. Your dermatologist can help determine the best treatment based on the type and severity of your condition.