The skin on the inside of the labia minora is smooth under normal physiologic conditions. The labia minora are a pair of longitudinal skin folds that surround the vaginal opening and are symmetrical. It is an important part of the female reproductive system and plays an important role in protecting the reproductive tract and urethra. In the physiological state, the labia minora are soft and free of subcutaneous fat, rich in sweat and sebaceous glands, and therefore moist and smooth. At the same time, the inner side of the labia minora is rich in nerve endings and is sensitive to external stimuli such as touch and pressure. The skin on the outside of the labia minora is deeply pigmented, brown or dark brown. The inner part of the labia minora is reddish or pinkish due to the presence of sweat glands and sebaceous glands, the absence of pubic hair, the abundance of blood vessels, and the lack of elastic fibers and smooth muscle. Consultation with a medical professional is recommended.