A hair doctor is typically called a trichologist. Trichology is the branch of dermatology that deals with the scientific study of the hair and scalp. Trichologists are trained professionals who specialize in the diagnosis and treatment of hair and scalp conditions. They have knowledge and expertise in understanding the structure, function, and diseases of the hair and scalp. They can help to diagnose and treat conditions such as hair loss, scalp disorders, and hair shaft abnormalities. They can also provide advice on hair care, hair styling and hair restoration. Some trichologists have a background in medical or cosmetology field, but not all of them.