The color of women's menstruation is brown, indicating that there is less vaginal bleeding, that is, less menstruation. There are many reasons for this. For example, women who have just finished abortion will experience a decrease in menstruation, which is mainly caused by damage to the endometrium. If women who have not performed uterine cavity operations have less menstruation, it may be caused by endocrine disorders, mainly because of abnormal ovulation, or because there is no ovulation, which leads to the decrease of estrogen level, thus reducing the amount of menstruation caused by endometrial thinning. It is suggested to go to the hospital in time for relevant examinations, such as B-ultrasound examination and sex hormone examination. After the cause is determined, symptomatic treatment should be given.