If the endometrium is not shed cleanly, it may cause irregular vaginal bleeding, vaginal dripping, long bleeding time, and heavy bleeding, and long-term endometrial shedding may cause endometrial lesions, endometrial hyperplasia, endometrial polyps, and serious endometrial cancer. Normal endometrium is exfoliated periodically under the action of ovarian hormones to form normal menstrual cycle. If ovarian dysfunction and hormone level disorder may cause endometrium not to be exfoliated completely, long-term endometrial exfoliation is not clean, it will cause endometrial thickening, polyp formation or endometrial cancer.