The clinical manifestations of menstruation are as follows: First, there will be periodic and regular bleeding from the vagina, which is related to the cyclical changes of the endometrium. Menstrual blood can flow from the vagina, which is the obvious symptom of menstruation. Second, the clinical manifestation is that the vagina or the endometrium will have abnormal secretion substances, which can be mucus or plasma, yellowish or white, and some secretions even have a certain smell, which is related to the elevated content of estrogen, sex hormone, progesterone, folliculopoietin and other hormones in the body during menstruation.