There may be many reasons for not having a period for more than 15 days, including menstrual disorders, pregnancy, polycystic ovary syndrome and pituitary tumors, etc., which need to be treated according to the actual symptoms and relevant examinations. 1. Menstrual disorders: excessive dieting, staying up late or intrauterine device placement can cause prolonged menstrual periods, reduced menstrual flow and other symptoms, accompanied by abdominal pain, dizziness, premenstrual irritability and other manifestations. If a woman of childbearing age has regular sex with menopause, loss of appetite, nausea, vomiting and other symptoms, pregnancy is suspected, blood HCG and ultrasound should be performed to confirm the diagnosis. 3.Polycystic ovary syndrome: often with scanty menstruation, irregular menstrual cycle, accompanied by hirsutism, acne, etc., serum hormone level measurement and ultrasound examination should be done to confirm the diagnosis, drug treatment can follow medical advice oral progesterone to regulate the menstrual cycle, daily attention to a balanced diet, active exercise, etc.; 4.Pituitary tumor: may have irregular menstruation, infertility, lactation, accompanied by headache, vision loss, etc. It is recommended that prolactin tests and pathological examinations be performed to confirm the diagnosis, and dopamine agonists and growth inhibitors can be chosen for drug treatment.