Patients who have menstrual blood that is black slag may have symptoms caused by gynecological inflammation, which is more common clinically in diseases such as endometritis or adnexitis, or it may be caused by the low amount of estrogen secretion in women’s bodies, resulting in a thinner endometrium, which leads to low menstrual blood. Therefore, if a patient has the above symptoms, she should go to the hospital for ultrasound and hormone tests, so that the cause can be clarified and treated according to the test results.