Gynecological diseases such as endometrial tuberculosis and polycystic ovary syndrome may prevent menstruation. Gynecological diseases that may prevent menstruation include endometrial tuberculosis, polycystic ovary syndrome, premature ovarian failure, uterine adhesions, cervical adhesions, thinning of the uterine lining, tuberculosis of the fallopian tubes, congenital ovarian dysplasia, congenital dysplasia of the uterus, ovarian inflammation, vaginal atresia, and hymenal atresia. The lack of menstruation may be a manifestation of the above gynecological diseases, or it may be a physiological change caused by pregnancy. Urine pregnancy test, pelvic ultrasound, laboratory tests, etc., are needed to clarify the cause of the lack of menstruation, and appropriate treatment will be carried out according to the cause of the disease.