Heavy menstrual flow may be caused by anemia, submucosal fibroids, endometrial polyps or ovarian diseases, which are analyzed as follows: 1. Anemia: In case of severe anemia, for example, blood dilution and menstrual flow will increase; 2. Uterine cavity diseases: For example, submucosal fibroids can increase the area of the uterine cavity and the area of the endometrium is relatively larger, which affects the contraction of the uterus and leads to heavy menstrual flow. And endometrial polyp can also lead to abnormal menstruation, manifested as excessive menstruation, prolonged periods or shortened menstrual cycles, or even intermenstrual bleeding, i.e., extra bleeding between periods; 3, endocrine abnormalities: such as estrogen or progesterone fluctuations, anovulatory menstruation, and abnormal endometrial hyperplasia, all of which can increase menstrual flow. In addition, such as poor luteal function of the ovaries, unstable or defective function of the hypothalamic-pituitary-ovarian axis, can also cause excessive menstrual flow. When patients find excessive menstrual flow, they should actively visit the gynecologist and cooperate with the doctor for gynecological examination, B ultrasound, colposcopy and other examinations to clarify the cause and develop a reasonable treatment plan.