The black color of the cervix may be due to endometriosis, cervical cancer and other diseases. 1. Endometriosis foci, endometriosis foci in the cervix, with the menstrual cycle, the blood gathered together may appear cervical black symptoms, generally no self-conscious discomfort. 2. Cervical cancer, some patients may have cervical cancer with tissue lesions in the cervical area and tissue necrosis and bleeding, which may lead to color change of the cervical opening, and thus black symptoms may appear. If there is such symptom, you need to actively consult a doctor for examination and treatment. In normal times, it is also necessary to pay attention to personal hygiene and do a good job in body care and health care.