The hymen is a thin membrane that surrounds the opening of a girl’s vagina. Typically it is shaped like a half moon, leaving space for menstrual blood to flow out of the vagina.
An imperforate hymen is when this thin membrane completely covers the opening of the vagina, blocking the flow of menstrual blood.
There may be no symptoms until a girl reaches puberty and is unable to have periods because the blood can’t flow out of the body. When the blood backs up into the vagina and abdomen, it can cause pain and discomfort.
Symptoms may include:
An imperforate hymen is typically diagnosed either in a newborn baby or at puberty when a girl
Diagnosis can be made through a physical exam.
Other differences in hymenal anatomy, including microperforate hymen and septate hymen, can also result in difficulty with periods or tampon use.