There are several reasons for the black color of bleeding at the beginning of menstruation: 1, due to the relatively small amount of bleeding in the early stage, the blood in the uterus can not be discharged in time, oxidation occurs to form black blood, this situation usually does not need to be dealt with, usually after the increase in the amount of menstruation can be relieved; 2, caused by cold or cold, before menstruation due to cold or cold uterus, resulting in slowing down the blood circulation, blood stagnation in the uterus, oxidation occurs This causes black menstrual blood, and most women will be accompanied by dysmenorrhea, you can first drink more brown sugar water, or oral motherwort granules to relieve; 3, the female cervix is too tight, premenstrual bleeding in the uterus can not be discharged in a timely manner, oxidation in the uterus to form black menstrual blood, you can observe a period of time, menstrual blood usually after the symptoms of their own relief; 4, chronic endometritis in the premenstrual period Due to inflammatory stimulation, a small amount of bleeding in the endometrium, affected by inflammation blood oxidation increased, the formation of black menstrual blood when discharged out of the body, you can take oral gynecological Qianjin tablets combined with broad-spectrum antibiotics for treatment.