It can be alarming to finish having sex and find you are bleeding. Seeing blood after intercourse refers to having vaginal bleeding during or just after sexual intercourse when you're not menstruating. This type of bleeding happens most often in women between the ages of 20 and 40. Vaginal bleeding after sex is not something to take lightly. There is a laundry list of possible causes. Here’s a rundown of some of the reasons for vaginal bleeding after sex.

A woman’s cervix, the narrow, lower end of the uterus, is usually the source of bleeding brought on by vaginal sex. This can be particularly true before menopause. If the cells of your cervix become inflamed or otherwise abnormal, sexual intercourse can cause enough friction to cause bleeding.

A woman may have suffered injuries to the vaginal wall or opening to the vagina during intercourse. Sometimes oral contraceptives or hormone replacement therapy can lead to bleeding after sex. Lowered estrogen levels in perimenopausal or postmenopausal women may cause the lining of the vagina to become thinned and easily inflamed or infected. These changes can be tied in with vaginal bleeding after intercourse.

Bleeding after vaginal sex may be an initial indication of endometrial or cervical cancer. However, more than likely, the cause is due to another condition. Sometimes the cause cannot be determined, but it's very important to be diagnosed by a physician to rule out cancer or any other diseases. Bleeding after vaginal sex is not normal, but in most cases, it's the result of harmless, treatable cervical changes, not cancer.

Sexually transmitted diseases or infections like gonorrhea and chlamydia can be a cause of vaginal bleeding after intercourse. Inflammation or swelling and infection of the vagina or cervix such as vaginitis or cervicitis can also bring about after-sex bleeding.

Another possible cause for bleeding after vaginal sex may be pelvic inflammatory disease (PID). Uterine fibroid tumors or polyps on the cervix or vaginal wall may also lead to vaginal bleeding during or after intercourse. Women with uterine polyps are known to experience vaginal bleeding after sex. Keep in mind these tumors are usually benign and rarely malignant.

Anytime you experience bleeding during or after vaginal sex when you are not menstruating, it's important to visit your doctor or health care provider to determine the cause. Getting an accurate diagnosis is critical. Even if the bleeding is due to something minor, it’s most likely treatable and better for your peace of mind.

Sources:
About.com Health’s Disease and Condition
MayoClinic.com
WebMD.com
MedicineNet.com