Normal menstrual bleeding is about 60 milliliters per month, more than 80 milliliters is too much and less than 20 milliliters is too little. Low menstrual flow often brings adverse psychological effects or infertility to patients. The main reasons for “low menstrual flow”: 1, endocrine factors: ovarian insufficiency, low estrogen level, hyperprolactinemia, or certain endocrine diseases such as thyroid dysfunction. 2.Congenital uterine dysplasia, endometrial estrogen receptor deficiency, endometrial tuberculosis, drug effects and so on. 3.Low menstrual flow after purging or abortion may be due to endometrial damage or uterine cavity adhesion, which is more common in clinic. Diagnosis and treatment: 1, first of all, gynecological examination and ultrasound, except for uterine development abnormalities. Measure the basal body temperature to understand the ovarian function; test the sex hormone level + TSH on the 2nd-5th day of menstruation (early follicular phase) to exclude the causes of hypomenorrhea such as ovarian insufficiency, hyperprolactinemia or thyroid function abnormality, etc. Measure the thyroid function if necessary. Measure thyroid function if necessary. 3.After the basal body temperature rises for about 7 days or 1 week before the onset of menstruation (mid-luteal phase), a vaginal ultrasound will be performed to check the thickness of the uterine lining to determine whether the uterine lining is underdeveloped. Normal endometrial thickness in the mid-luteal phase is about 0.5-0.8cm (single layer). 4, suspected of uterine adhesions, hysteroscopy. If there are uterine adhesions, hysteroscopy will be performed to decompose the adhesions. 5, for ovarian insufficiency, low estrogen level, congenital uterine dysplasia, uterine cavity adhesion decomposition after surgery, etc. for estrogen and progesterone cycle treatment. Experts believe that the treatment cycle for menorrhagia should be relatively long, at least six menstrual cycles. 6.Chinese medicine treatment.