What is the reason for the sudden decrease in menstruation?

A woman's normal menstrual flow is 20 to 60 ml. If a woman's menstrual flow suddenly becomes less, consider the following reasons: first, whether there is a possibility of pregnancy, first of all, to rule out abnormal uterine bleeding caused by pregnancy, it is recommended to do blood HCG and urine pregnancy test to rule out pregnancy. Second, whether there is endocrine disorders caused by menstrual flow reduction, it is recommended to do sex hormone six and thyroid function test to rule out endocrine disorders caused by menstrual flow reduction. Third, whether there should be uterine surgery history caused by endometrial damage, and caused by endometriosis, endometrial adhesions and other manifestations caused by reduced menstrual volume. It is recommended to do gynecological B ultrasound, to understand the situation of the endometrium, and whether there are adhesions in the uterus. If there are uterine adhesions, it is recommended to do hysteroscopic adhesion separation and lysis.