Which department should I visit for hair loss?

Hair is a skin appendage; thus, diseases affecting the skin and its appendages fall within the scope of dermatology. Therefore, hair loss should be evaluated by a dermatologist. Hair loss—also known as alopecia—generally falls into two main categories: alopecia areata and androgenetic alopecia. Alopecia areata presents as well-demarcated, patchy hair loss. Lesions may involve a single patch or multiple patches; in severe cases, complete scalp hair loss (termed “alopecia totalis”) may occur. Occasionally, loss of axillary and pubic hair may also develop, termed “alopecia universalis,” and this condition is associated with autoimmune mechanisms. Androgenetic alopecia—also referred to as male-pattern (or female-pattern) baldness—is caused either by elevated levels of androgens or by a genetic predisposition leading to heightened sensitivity of hair follicles to the biological effects of androgens (which exert a negative regulatory effect on hair follicles).