The causes of menstrual clots are the following: 1. physiological clots, menstrual flow to the 2nd-3rd day bleeding more, so that the endometrium and necrotic epithelial cells together with the formation of clots, if the bleeding is not much and is occasional, do not worry too much. 2. endocrine disorders, if the ovaries secrete too much estrogen or estrogen for a longer period of time to stimulate the endometrium, so that the endometrium proliferates more than the normal thickness, the bleeding will increase when shed, will appear clots. 3. normal thickness, the bleeding will increase when shedding and clots will appear. 3, gynecological pneumatological diseases, such as uterine fibroids, endometriosis, adenomyosis, uterine polyps, etc., due to high bleeding and the formation of clots. 4, systemic diseases, if suffering from leukemia, aplastic anemia, thrombocytopenia, liver disease, etc. 5, due to mental factors or stimulation from cold and other aspects, so that the menstrual volume is too The clot is formed when the anticoagulant substance is too fast to work.