The menstrual cycle and the amount of menstrual bleeding in women are related to changes in body status, hormone levels in the body, and external environmental influences. The normal menstrual cycle for women is 28 days on average, and it is normal to be within 7 days early or late, that is, the menstrual cycle is normal between 21-35 days, and the menstrual bleeding time for women is normal within 3-7 days. The amount of menstrual bleeding in women should be around 50 ml. Changes in the external environment such as temperature changes and changes in work and rest habits may cause changes in the menstrual cycle, and abnormalities in the thickness of the endometrium caused by disorders in the body’s hormone levels may also cause changes in the menstrual cycle and the amount of bleeding. If the change is beyond the normal range, you can check the endometrial thickness by ultrasound, check the hormone level in your body, and make adjustments according to the test results.