Menstruation is a physiological period that comes every month for women, and under normal circumstances, the amount of menstruation is relatively fixed, which is about 60ml. Causing women to have more than one month and less than one month may be a pathology, that is, endocrine dysfunction or organic pathology, menstrual flow is called excessive menstruation in medical books, if the period is more than 10 days is called prolonged menstruation. Increased menstrual flow may be caused by gynecological inflammation, uterine fibroids, pelvic infection, endometriosis, adenomyosis, and decreased menstrual flow may be caused by endocrine dysfunction. It is not normal for a woman to have more than one month and less than one month. It is recommended to go to the hospital for an ultrasound examination as well as a hormone test to clarify the cause of the disease and to have it treated in a timely manner so as not to affect the body.