Black vaginal discharge is related to menstruation and may be caused by early menstruation. When menstruation occurs early, the amount of menstrual blood is low, and the blood pools in the uterine cavity, changing its color to black mucus. It is also related to ovulation bleeding, if it occurs about 14 days before menstruation, it is ovulation bleeding. At this time, intercourse should be good contraceptive measures to avoid unwanted pregnancy. Black mucus can also appear in the vagina when suffering from gynecological diseases, such as cervical inflammation, vaginal inflammation, endometrial inflammation, ovarian inflammation and so on. Sex hormone six tests and ultrasound can be performed, and adjustments can be made according to the results. When suffering from inflammation must be actively treated, otherwise it will aggravate the condition. There is black mucus should pay attention to private hygiene, wash with warm water every day or use antiseptic and anti-itch lotion, but can not take drugs privately.