Most of the unmarried girls with big black nipples are due to high hormone levels, pigmentation, heredity, breast diseases and other effects. 1. High hormone levels: If the girl’s body estrogen level is high, and the nipple is more sensitive to estrogen, it will lead to nipple color gradually become darker. 2. Hyperpigmentation: If you overstimulate your nipples or wear relatively rough underwear, it will lead to localized friction, which will result in the formation of melanin pigmentation, leading to darkened nipples. 3. Heredity: If there are relatives or mothers with big black nipples in the family, they will also have big black nipples due to hereditary reasons. 4. Breast Disease: Women with large black nipples may have bloody secretions, generally eczema-like cancer of the nipple, breast cancer will have similar symptoms, accompanied by breast inversion and other abnormalities, you can go to the regular hospital to do the relevant examination. Unmarried girls nipple big black with discomfort, it is recommended to timely in the regular hospital, under the guidance of the doctor standardized treatment.