Aunt generally refers to menstruation. Black menstrual blood may be caused by physiological factors such as unstable emotions and irregular life, or it may be caused by pathological factors such as endometritis, tuberculous pelvic inflammation, uterine fibroids and other diseases. 1. Physiological factors: Physiological factors such as bad mood, irregular life and mental stimulation can cause dark menstruation. 2. Pathological factors: dark menstruation can also be caused by diseases, such as inflammation, tumors, and so on, common endometritis, tuberculous pelvic inflammatory disease, uterine fibroids and so on. When the symptom of dark menstruation occurs, you should go to the regular hospital for diagnosis, clarify the cause of the disease and follow the doctor’s instructions for treatment, and you should pay attention to maintaining a happy spirit, paying attention to hygiene and preventing infections in your daily life.