The total volume of each menstrual period in a normal person is between 50 and 60 ml. The amount of menstrual blood is not exactly the same for each person, and even the same person does not have the same amount of menstrual blood each time. If the menstrual cycle is normal and the amount of menstrual blood is less than 10 ml or so little that it is not even wet through two layers of paper, it is considered a low menstrual flow. The pathology of low menstrual flow has deficiency and reality. The deficiency is caused by weakness, serious illness, prolonged illness, loss of blood or diet and fatigue injury to the spleen, or room strain injury to the kidneys, resulting in deficiency of blood and reduced menstrual flow; the reality is caused by stagnant blood, or phlegm and dampness congestion, obstruction of the menstrual vessels, poor blood flow and reduced menstrual flow. In summary, the causes of low menstrual flow are generally the following: 1. Low menstrual flow can occur in women who are on excessive dieting. 2. Women who work and rest in an inordinate manner are prone to low menstrual flow because women are stimulated by cold during their periods, which can cause excessive pumping of the blood vessels in the pelvic cavity, which can produce low menstrual flow or even amenorrhea. 3, sulking or meeting important soul stimulation and psychological trauma, are prone to low menstrual flow in young girls. 4, In addition, it may be the cause of the endometrium itself, such as endometrial lesions caused by endometrial tuberculosis or thin endometrium caused by abortion and scraping. 5, endocrine reasons, such as abnormal secretion of various hormones or non-ovulation, etc. 6, tumor, uterine dysplasia and other diseases.