The hymen (derived from Hymenaeus, the god of marriage and the wedding ceremony in ancient Greek mythology) is a membranous tissue 2 to 3 mm thick, located 2-3 cm inside the vaginal opening and partially covering the entrance of the external genitalia in women. This tissue, which can have various shapes, is usually in the form of a crescent. It is located at the entrance of the vagina and is surrounded by thin capillaries.

Although the hymen is usually thought to be a membrane because of its name, it is not actually a true membrane. It has no known anatomical function. It is believed to prevent microorganisms from entering the vagina prior to fertility.

This tissue loses its integrity during the first sexual intercourse (also called first night, first vaginal penetration), and as a result, a little bleeding occurs.

The hymen may lose its integrity and bleed due to cycling, horseback riding, falls from a great height, masturbation, sexual intercourse, and friction. The hymen takes on its shape and the characteristics of its structure during the embryonic period, and 1 in 1000 women are born without a hymen.

If couples have sexual knowledge before the first sexual intercourse, they will have less fears and prejudices on this topic. One of the most important causes of vaginismus is the fear that the hymen may tear, bleed and hurt.