Black nipples are usually caused by physiological factors, but may also be caused by pathological factors. 1. Physiological factors: during puberty, pregnancy, menstruation and other special periods of time, due to hormonal fluctuations in the body caused by melanin deposition, nipple black can occur. Black nipples can also be caused by heredity. Nursing women, because the baby sucks the nipple, stimulate melanin cells, resulting in melanin gathered in the nipple, nipple black. 2. Pathological factors: Melanoma occurring in the nipple area can appear nipple black. Trauma, infection, etc. can lead to nipple necrosis, manifested as blackened nipples, and can also be accompanied by pain, nipple discharge and other symptoms. There are many causes of nipple blackening, and if nipple blackening is accompanied by other discomforts, it is recommended to go to the hospital in time.