The normal menstrual volume for women is between 30 and 80 ml. If the volume of each period is less than 30 ml, it is considered as scanty menstruation. If the menstrual volume is particularly low, several conditions should be considered: the first one is unstable ovarian function, endocrine abnormalities, women with polycystic ovary syndrome tend to have scanty menstruation; the second one is uterine adhesions or cervical adhesions, patients with these two diseases usually have scanty menstruation or no menstruation. These patients usually have a history of uterine operation, i.e., abortion or uterine evacuation; the third consideration is pregnancy, when pregnancy is followed by menstruation, some women may have a little bleeding when they are about to have their period.