If the menstrual flow is low and the number of days of menstruation is also very low, clinically it is commonly caused by the following reasons: First, the ovarian function declines, most of them occur during the perimenopause, if the age is less than 40 years old, it may also be caused by premature ovarian failure. Second, taking a certain drug, such as long-term use of short-acting contraceptives to give contraception, resulting in thinning of the endometrium, so it can cause a significant reduction in menstrual flow. Third, if there is a recent history of uterine operation, it may cause damage to the endometrium and lead to incomplete adhesions in the uterine cavity, which may also cause a significant decrease in menstrual flow, so it is necessary to combine medical history and examination before deciding what to do next.