The menstrual volume of women is within the normal range of 5-80mL. Some women have very little menstrual volume from the beginning of menstruation, and there is no discomfort and no problem with the examination, which is normal. Some women have a normal menstrual flow, but after having an intrauterine operation such as abortion, curettage or curettage, the menstrual flow decreases, so it is necessary to consider whether the endometrium was damaged during the intrauterine operation, which may cause thinning of the endometrium and adhesions in the uterine cavity. Some women also talk about normal menstrual flow, but then it suddenly increases. In this case, it is necessary to consider whether there is a combination of endometrial hyperplasia, polyps, submucosal fibroids, or adenomyosis, and it is necessary to do tests to clarify the diagnosis and exclude the pathological condition of increased menstrual flow.