Low menstrual flow refers to less than 2 days of menstruation and less than 30ml of menstrual blood. The common causes of low menstrual flow are as follows: 1. endocrine disorders, excessive mental stress, excessive mental stimulation, overwork, staying up late, irregular diet, etc., all tend to lead to endocrine disorders, which affect menstruation and make it low. 2. excessive weight loss, female menstruation is related to body weight and body fat content. If the weight is too low and the body fat is too little, the menstrual volume will be reduced and even amenorrhea will occur. 3, ovarian function decline, ovarian function directly affects women’s menstruation, if the follicles are poorly developed and estrogen secretion is reduced, it is easy to cause a decrease in menstrual volume. 4, abortion, frequent abortion, scraping, will make the endometrium thinner and thinner, abortion is also prone to uterine adhesions, which are all causes of The reason for the decrease of menstrual flow.