The first thing to look for when it comes to low menstrual flow is to see a gynecologist. For what causes the low menstrual flow to occur, the first step is to do further examination and judgment based on the specific age of the patient. First of all, for young women in puberty, low menstrual flow is mostly due to the fact that the ovaries are not fully established and the ovaries do not ovulate, resulting in the continuous growth of the endometrium, or the growth of the endometrium is in a bad condition resulting in low menstrual flow. In cases where the ovarian function has been gradually established, the low menstrual flow may be due to the lack of ovarian function and luteal function. In women who are in the perimenopausal stage of menopause, low menstrual flow may also occur due to the gradual decrease in ovarian function of the non-ovulatory ovaries.