Post-coital bleeding isn’t necessarily a sign of something bad.
Unless you’re on your period, experiencing bleeding after sex can certainly feel alarming. It may not be super common, but it’s certainly not unheard of (and not necessarily a sign of something bad). According to a 2014 study conducted by the Womack Army Medical Center, post-coital bleeding that isn’t period-related occurs in anywhere from .7 to 9 percent of women who menstruate.
Sloane York, MD, an obstetrician-gynecologist at Rush University Medical Center in Chicago, says that the source of the blood is typically the cervix. Blood can also originate from inside the uterus or the side of the vagina, depending on the cause. For young women, a number of reasons could be behind post-coital bleeding. “Some women will have generally irregular periods and on-and-off bleeding, and may notice [themselves] bleeding more prominently after sex,” York says.
Bleeding can also be due to normal changes in the cervix. Hormonal changes such as those that occur during pregnancy can cause some women to develop cervical ectropion, for example: That’s where the cervical canal turns outward, exposing tissue with fragile blood vessels that bleed easily when they’re touched by, say, a penis or fingers. (This generally doesn’t require treatment or have symptoms other than post-coital bleeding.) Benign cervical polyps, which are “abnormal growths of polypoid tissue from the cervix and are rarely related to cancer,” can also make the cervix prone to bleeding.