Alopecia areata is a type of hair loss that occurs when your immune system mistakenly attacks hair follicles, leading to patchy bald spots. It's most common in young adults and children but can occur at any age. The condition is not contagious or life-threatening, but it can cause emotional distress due to the appearance of bald spots on the scalp. Treatment options include medications, corticosteroid injections, and lifestyle changes such as stress management.