[5] The hymen can rip or tear during first penetrative intercourse, which usually results in pain and, sometimes, mild temporary bleeding or spotting.

[6] Historically, it was believed that first penetration was necessarily traumatic, but now sources differ on how common tearing or bleeding are as a result of first intercourse.

At week twelve, the Müllerian ducts fuse to create a primitive uterovaginal canal called unaleria.

At month five, the vaginal canalization is complete and the fetal hymen is formed from the proliferation of the sinovaginal bulbs (where Müllerian ducts meet the urogenital sinus), and normally becomes perforate before or shortly after birth.

In newborn babies, still under the influence of the mother's hormones, the hymen is thick, pale pink, and redundant (folds in on itself and may protrude).

[3][4]The hymen can stretch or tear as a result of various behaviors, by the use of tampons[7] or menstrual cups, pelvic examinations with a speculum, or sexual intercourse.

[15][16] The only variation that may require medical intervention is the imperforate hymen, which either completely prevents the passage of menstrual fluid or slows it significantly.

From puberty onwards, depending on estrogen and activity levels, the hymenal tissue may be thicker, and the opening is often fimbriated or erratically shaped.

[25][27] In a study of adolescents who had previously had consensual sex, approximately half showed evidence of trauma to the hymen.

[25][29][1] An observational study of adolescent sexual assault victims found that majority of wounds to the hymen healed without any visible sign of injury having occurred.

[37] In the 16th and 17th centuries, medical researchers mistakenly saw the presence or absence of the hymen as founding evidence of physical diseases such as "womb-fury", i.e., (female) hysteria.

[38][39] Due to similar reproductive system development, many mammals have hymens, including chimpanzees, elephants, manatees, whales, horses and llamas.