What is a hymen?

The hymen is a fold of tissue within the vagina that partially covers the opening. The hymen is usually there at birth, although people can also be born without a hymen. Hymens can be different shapes and sizes. The hymen is flexible tissue, and it usually stretches/wears away during childhood from activities like bike riding or gymnastics. If the hymen hasn’t stretched/ worn away and someone has vaginal sex, it might partially block the partner from entering the vagina. If the sex is forceful, it can tear, causing bleeding and pain. Because the hymen is flexible, it doesn’t always tear from sex.