Hymen

Patient's question:

1. What does the hymen look like? Is it a transparent membrane (like plastic), or a thin flesh membrane? Can it be seen with the naked eye?
2. Where is the hymen located in the vagina? I noticed that there is a semi-circular opening in my vaginal area. Is this the vaginal opening, or the opening of the hymen?
3. Does the vaginal opening appear as a visible hole? I’ve seen some external genital diagrams that directly draw a hole, but is it really that obvious in reality? Meanwhile, they depict the hymen on the left side of the vaginal opening, yet it seems like there’s nothing there. What exactly does the hymen look like? Could you please describe it in detail for me? Thank you.

Doctor's answer:

Hello: The vaginal opening of a virgin also has a ring-shaped mucosal fold called the hymen, which is a thin, membrane-like tissue containing connective tissue, blood vessels, and nerve endings. It can serve to partially close the vagina. The inner edge of the hymen is sharp and intact, and the hymen of an unmarried woman is usually light red. The hymen is typically not completely sealed, with a small opening in the middle to allow menstrual blood to flow out after puberty.
The shape, size, and thickness of the opening can vary from person to person. The hymen of an unmarried woman is usually crescent-shaped or elliptical, but it can also be sieve-shaped, radiating, fish-mouth-shaped, or other shapes. Its size also varies, with some so small that even a finger cannot pass through, while others are large enough to accommodate two fingers. The hymen is generally about 2 millimeters thick and often tears during the first sexual intercourse, though there are exceptions. Some hymens are too narrow or thin and may tear during exercise, vibration, or when inserting a menstrual.
From a sexual perspective, people are more concerned about the vagina because it is directly related to sexual activity. People jokingly call it a "hole" or a "barrel," but it is actually not a cave—it is a closed space, somewhat like a balloon. The vaginal walls are normally tightly pressed together but can expand fully when needed. The vagina is actually a highly elastic muscular organ that can contract and relax. When contracted, even a small finger cannot fit inside, but when relaxed, the penis can be inserted or moved freely, even allowing a fetus to pass through.
A woman's vagina can vary greatly in tightness. Unmarried women's vaginas are generally tight and elastic, but after giving birth, the vaginal walls become looser. Many people lack awareness of the vagina's potential for contraction and relaxation. Men may worry that penis insertion will harm their partner, and women may fear that sexual intercourse will hurt them. However, such concerns are entirely unnecessary. The vagina's potential for expansion and adjustment can sometimes be quite remarkable.
Some people worry that a too-narrow vagina will restrict penis insertion. In reality, both truly small vaginas and truly small penises are rare. The issue often lies in the woman's response during insertion. If the woman is highly aroused, even a large penis will not be a problem. Conversely, if the woman is not aroused, even a small penis may cause issues. Women who have been abstinent for a long time or those postmenopausal may have slower sexual responses when resuming intercourse. Therefore, avoid inserting the penis until the woman is highly aroused, as otherwise, it may only bring her pain rather than pleasure.
When obstetric injuries cause excessive vaginal relaxation, not only does it significantly reduce the woman's external and proprioceptive sensitivity during intercourse, but it also affects her response to the man's external stimuli, though not as severely. In such cases, Kegel exercises can help restore the muscle's tension, elasticity, and regulatory ability.
In adult women, the anterior wall of the vagina is shorter, about 7–9 centimeters long, while the posterior wall is longer, about 9–12 centimeters. Normally, the anterior and posterior walls are tightly pressed together, giving the vagina a cross-sectional "H" shape. The upper part curves downward and backward, approaching the sacral fossa, while the lower part curves forward, giving the vaginal sagittal plane an "S" shape. The upper part of the vagina is wider and surrounds the cervix. The ring-shaped cavity between the cervix and the vaginal wall is called the vaginal fornix, which is divided into anterior, posterior, and left and right parts based on its location. The posterior fornix is particularly deep and wide, acting as a seminal reservoir. During the lithotomy position, the posterior fornix is the lowest part of the vagina, which facilitates sperm movement from the vagina to the cervix, as the external orifice of the normally positioned cervix faces the posterior fornix. The posterior fornix is the most easily expandable part of the vagina, providing necessary space for an erect penis while preventing excessive cervical displacement and potential sexual difficulties.