A lot of people don’t know what the hymen really is – even doctors. People generally think that the hymen is ‘something’ in the vagina that seals it off until you have had sex or until you are no longer a virgin. This is not true.
First of all, the hymen is not technically in the vagina. It is a thin layer of tissue outside the vagina (in the vulva) that partially conceals or covers up the vagina. When a female foetus is developing in the womb, there is originally no opening or hole in the hymen, but an opening develops by the time the baby is born. Long before you lose your virginity, your hymen already has an opening.
There are some women who do not have an opening in their hymen because normal development did not occur in the womb. This is a problematic medical condition known as imperforate hymen. Once a girl begins menstruating, if there is no opening in her hymen, then the menstrual blood builds up in the uterus and vagina. This is not a common problem; it only occurs in 1 in 2,000 females. An imperforate hymen is rarely diagnosed until girls begin menstruating and they discover a big, painful mass in their belly around the time of their period (a mass of blood that cannot exit the vagina). In order to fix an imperforate hymen, a doctor must perform surgery to create an opening in the hymen.