Women’s armpit hair is divided into physiological and pathological, physiological armpit hair is mainly related to genetic factors, physiological armpit hair may be due to hirsutism, adverse reactions to topical drugs and other conditions. 1. Physiological factors: women’s armpit hair may be caused by genetic factors, if the parents have more armpit hair, the chance of their children having more armpit hair will also increase. 2. Hirsutism: mostly manifested as the local appearance of more, coarse, dense hair, hair growth site can be divided into generalized or limited, some female patients will appear in the case of armpit hair. The cause of this disease may be caused by endocrine abnormalities, external stimuli and other factors. In addition, excessive hairiness in women is usually caused by polycystic ovary syndrome. 3. Adverse reaction to topical medications: Because the armpits suffer from dermatitis eczema and other diseases, the long-term use of glucocorticoid ointments such as mometasone furoate, hydrocortisone butyrate ointment, etc., will also appear in the case of armpit hairy armpits. There is no unique reason for a woman to have a lot of armpit hair, and after ruling out physiological factors, patients are advised to seek medical examination to clarify the cause.