The hymen is just a membrane that covers the vaginal opening and is about 1-2mm thick. The thickness and shape of the hymen varies due to individual differences. The shape of the hymen is overwhelmingly round and has a hole in the middle, while some people have a sieve-shaped or triangular hymen, and the vast majority have a round hymen. The thickness of the hymen varies from person to person, with some being slightly thicker and others thinner, both of which are normal. Often the hymen is ruptured during sexual intercourse and only a trace of the hymen is visible after vaginal delivery. In clinical practice, not everyone’s first sexual intercourse will result in a ruptured hymen, mainly because some people have relatively large hymen holes, so that they do not rupture and bleed.