The ovarian tissue will be damaged, thus affecting the normal menstruation and leading to prolonged menstrual cycle, or even serious cases will lead to amenorrhea; 3, endometrial destruction: If the endometrial lining of the uterus is destroyed, it may also lead to prolonged menstrual cycle. Endometrial destruction includes many hidden factors, such as endometrial tuberculosis, but also some patients because of childbirth or abortion, excessive scraping caused by the endometrial basal layer damage; 4, pelvic inflammation: in real life, many women have pelvic inflammatory trouble, inflammation if not controlled in time, may lead to poor blood circulation in the uterus, and even lead to the degeneration of endometrial necrosis, as well as pelvic stasis, which can lead to prolonged menstrual cycles and even serious cases of amenorrhea; 3, endometrial destruction: if a woman is destroyed, it may also lead to prolonged menstrual cycles. as well as pelvic stasis, thus causing the phenomenon of long menstrual cycle; 5, other: such as bad mood and other factors, may also lead to prolonged menstrual cycle.