Increased armpit hair in middle age may be a normal phenomenon caused by endocrine disorders, or it may be caused by polycystic ovary syndrome, Cushing’s syndrome and other diseases. 1. Normal phenomenon: female patients to middle age, the body hormone with age, there will be certain changes, will lead to female patients appear armpit hair increase phenomenon, this situation is a normal physiological phenomenon. 2. Polycystic ovary syndrome: the cause of polycystic ovary syndrome has not been clarified so far, and it is considered to be caused by a combination of genetic and environmental factors. The main symptoms of patients are abnormal menstruation, acne, hairiness, infertility, etc. Hair loss, obesity, acanthosis nigricans and other symptoms will also occur. 3. Cushing’s syndrome: Cushing’s syndrome is mainly caused by excessive secretion of glucocorticoids by the adrenal cortex, and patients will have symptoms such as centripetal obesity, elevated blood pressure, abnormal glucose metabolism, acne, and hirsutism. In addition, patients with Cushing’s syndrome may experience scanty menstruation and a dark reddish color. When female patients experience increased armpit hair, if it is a normal phenomenon caused by hormonal changes, no treatment is needed. If it is caused by a disease, timely medical treatment is needed.