1, excessive sexual life. The blackening of private parts is related to excessive skin friction of private parts, especially for girls who have frequent sexual life. The labia minora has been repeatedly stimulated by external friction for a long time, resulting in increased local pigmentation. At the same time, the melanin of hormones during sexual stimulation will also turn the labia into a black halo.

This dress is too tight. Wearing too much underwear on weekdays will oppress blood circulation. When the blood circulation is not smooth, melanin tends to sink, and your skin color tends to become darker.

3. Genetic factors. It is genetic factors that determine the primary colors of nipple or labia majora and labia minora. Heredity determines the number of melanocytes, as well as the synthesis and metabolism of melanin, and the depth of skin color is related to melanin. Therefore, even if there is no sex life and no pregnancy, the privacy of effective women will turn black.

4. Pigment accumulation. The color of female genitalia is influenced by its own melanin precipitation and is also related to female hormones. With the growth of age, affected by hormone secretion, melanin in private parts accumulates more and more, and the color turns black.