Menstruation coming 10 days earlier is definitely a problem, belonging to abnormal uterine bleeding, which is commonly caused by the following reasons: First, early menstruation caused by insufficient function of the corpus luteum, it is suggested that progesterone can be supplemented in the second half of the menstrual period. Secondly, due to submucous fibroid of uterus, the area of uterine cavity will be enlarged and the uterus will contract poorly, irregular vaginal bleeding will occur, which will also lead to shortening of menstrual cycle and the amount of menstruation will be increased, and ultrasound examination is needed. Thirdly, if the menstruation is more than 10 days early, it is considered to be caused by the inflammation of the endometrium, due to the inflammation of the endometrium, the localization is brittle, and there will be irregular shedding, which will lead to early menstruation. Diseases of the endometrium can also lead to early menstruation. If the endometrium is relatively thick after ultrasound examination, diagnostic scraping must be done to exclude diseases of the endometrium.