Aunt substitute for menstruation, menstruation is black considerations related to low menstrual flow. For women who usually have low menstrual flow, there is no need to be nervous as the menstrual blood remains in the vagina and cannot be discharged in time, and becomes black due to oxidization reaction in the vagina. Low menstrual flow may be related to multiple abortions, polycystic ovary syndrome, premature ovarian failure and other gynecological endocrine diseases, and if necessary, should consult a doctor for a clear diagnosis. Meanwhile, for those who get cold or drink cold water before and during menstruation, it can also lead to poor menstrual blood flow and black menstrual color, abdominal pain, back pain and other discomforts, so for women to pay attention to warmth during menstruation. For women with black menstruation, it is recommended that they go to the gynecology department of a regular hospital, complete the gynecological ultrasound and other relevant examinations, and then actively treat the cause of the disease.