Hair above the buttocks is usually divided into physiological and pathological, physiological hair above the buttocks refers to anal hair, which is a normal physiological phenomenon. Pathological hair on the buttocks may be caused by hirsutism, adverse reactions to topical ointments and other conditions. 1. Physiological factors: Hair above the buttocks refers to the anal hair, belongs to the natural physiological phenomenon, mostly after puberty. 2. Hirsutism: Clinical manifestation is that a large number of long and thick hairs appear in the parts that should not be hairy, or longer, more and thicker hairs appear compared with the normal gender and age, and some patients will have hairy situation above the buttocks. The causes of hirsutism are mostly related to heredity and increased androgen levels. If a woman suffers from hirsutism, it may also be caused by polycystic ovary syndrome. 3. Adverse reaction of topical drugs: If the buttocks suffer from dermatitis and eczema, after long-term local topical glucocorticoid creams such as hydrocortisone butyrate, the situation of hairy buttocks will also occur. There are many reasons why hair grows on the buttocks, after excluding physiological factors, it is recommended that patients seek medical examination to clarify the cause of the disease.