The most common reasons for early menstruation in women are the following: First, endocrine disorders, such as luteal insufficiency. When luteal insufficiency occurs, withdrawal bleeding appears earlier, so menstruation will be early. Second, in case of submucosal fibroids, the uterine cavity will be relatively larger and the endometrial area will be relatively larger, which will affect the contraction of the uterus and make the menstrual cycle shorter and the menstrual period will be longer, and there will be incessant vaginal bleeding. Thirdly, polyps in the endometrium, due to polyps in the endometrium, which is equivalent to a foreign body in the endometrium, make the uterus contract poorly and lead to early menstruation. Therefore, women with early and delayed menstruation must go to the hospital to find out the cause, and then give treatment according to the cause.