The hymen is usually visible. Hymen is about 5cm from the vaginal opening, is a layer of membrane tissue, composed of connective tissue, nerve endings and blood vessels, most of the ring-shaped fold shape, the center of the hymen hole, is the channel for menstrual blood flow. The hymen is thicker at an early age and has a protective effect. As a woman grows older, the vaginal microenvironment is formed and the vagina itself has a self-purifying effect, it will become weaker, causing the hymen to rupture during sexual intercourse or strenuous exercise or riding across the action. Hymen rupture will have pain and a small amount of bleeding, but this is not absolute, some women hymen toughness is very large, the first intercourse is not necessarily ruptured.