The darkening of the vulva is a normal physiological change that is related to the increase of hormone levels in the female body after puberty and to the physical condition of the female body: 1) It may be related to heredity and individual physical factors. 2) It may also be due to excessive friction of the vulva during sex, which may cause the vulva to darken. 3) It is mainly related to the increase of estrogen, progesterone, and melanin secretion in the female body after puberty, which may lead to hyperpigmentation and darkening of the vulva. 4) It may be related to the increase of estrogen and progesterone in the female body after puberty. Estrogen, progesterone, and increased secretion of melanin-stimulating cells have a major relationship, which can lead to hyperpigmentation and darkening of the vulva. If there is no itching, dryness, redness or swelling of the vulva, women should eat more nutritious food and maintain a regular life, so that they can observe the condition for the time being. If women have vulvar itching and odor, it is mostly due to vulvar inflammation and vaginal inflammation, which need to be treated with lotion or medicine in time.