Menstruation is also known as menstruation. Delayed menstruation is considered to be caused by physiological factors (e.g. pregnancy, etc.) or pathologic factors (e.g. ovarian hypoplasia, hyperthyroidism, etc.). Physiological factors generally do not require any treatment, while pathologic factors can be treated through medication, surgery, and so on. 1. Pregnancy: When a woman is pregnant, the elevated level of estrogen and progesterone will inhibit ovarian ovulation, so she will not menstruate in case of pregnancy. In addition to the absence of menstruation, pregnancy is also accompanied by nausea, vomiting, loss of appetite, drowsiness and other symptoms, usually without treatment. 2. Ovarian hypofunction: the main function of the ovaries is ovulation and secretion of estrogen and progesterone, ovarian hypofunction may affect the menstrual cycle, usually accompanied by low menstrual flow, fatigue and insomnia, etc., and can be treated by taking Progesterone capsules, dydrogesterone tablets and other medications as prescribed by the doctor. 3. Hyperthyroidism: Hyperthyroidism usually manifests itself in low menstrual flow, prolonged menstrual cycle or amenorrhea, and may be accompanied by weight loss, irritability, goiter and other symptoms. Hyperthyroidism can be treated with medications such as propylthiouracil and methimazole as prescribed by the doctor, and if necessary, surgical removal can be chosen. Normal menstrual cycle is generally 21~35 days, menstruation advance or delayed up to 7 days are normal phenomenon, if more than seven days, it is recommended to go to the regular hospital in time to do a comprehensive gynecological examination, to clarify the cause of the cause of the disease and actively cooperate with the treatment.