Usually, menstruation is very regular, but when it comes to menstruation but no tide, but there is a brown discharge, mainly consider four possibilities: First, episodic menstrual disorders, when there is a drastic change in the weather, seasonal change or increased stress, mental tension, environmental changes, excessive dieting, weight loss and many other triggers appear, can appear episodic menstrual disorders, do not need treatment, pay attention to observe the next menstruation If there are two or more low menstrual periods in a row, it is necessary to investigate and treat. Secondly, low menstrual flow caused by endometrial damage or adhesions, patients mostly have a history of abortion and scraping, IUD release or hysteroscopy and other uterine operations. Third, women with ovarian hypofunction caused by perimenopausal women with sudden decrease in menstrual flow or amenorrhea due to ovarian hypofunction. Fourthly, abnormal bleeding caused by pre-eclampsia or ectopic pregnancy is not true menstruation and can be clearly diagnosed by checking progesterone HCG and ultrasound.