Types of Hair Loss Hair loss, also called alopecia, is a disorder due to an interruption in the body’s cycle of hair production. Hair loss can occur anywhere on the body, but most commonly affects the scalp. On average, the scalp has 100,000 hairs that cycle through growing, resting, falling out, and regenerating periods. A hair growth cycle consists of three phases. During the anagen phase, hair grows actively. This phase may last for years. During the catagen phase, hair stops growing and separates from its follicle, which is the structure beneath the skin that holds the hair in place.…