If menstruation does not come, the following reasons are common in clinical practice:1. If you have normal sexual life and do not take contraceptive measures, it may be due to the menopause caused by pregnancy.2. Menopause due to endocrine disorders, such as prolonged work pressure, mental tension or sudden environmental changes, suffering from cold stimulation, and often staying up late, may lead to endocrine disorders and cause menopause.3. Menopause caused by certain diseases, such as polycystic ovary syndrome, endometrial tuberculosis, and hyperprolactinemia.4. The lack of menstruation caused by certain diseases, such as polycystic ovary syndrome, endometrial tuberculosis, hyperprolactinemia. 4, due to repeated abortions, resulting in endometrial damage caused by uterine adhesions leading to amenorrhea.