Hymen is a membrane that surrounds or partially covers the external vaginal opening. The hymen often, though not always, rips or tears the first time a female engages in penetrative intercourse, which may cause some temporary bleeding and slight discomfort. The hymen can also stretch or tear as a result of laceration by disease, injury, medical examination, masturbation or physical exercises. The hymen does not regenerate itself after it is torn, but may be surgically restored or repaired. This surgery may be of importance for whom an intact hymen is an indicator of virginity .