Bleeding after sex: causes, when to worry, and what to do

The most common causes

Cervical ectropion (cervical erosion). This is the most frequent cause in younger women. Cells from the inside of the cervical canal extend onto the outer surface of the cervix, where they are more fragile and bleed easily with friction during sex. It is harmless. It is more common in women on the combined pill or who are pregnant, because oestrogen encourages these cells to move outward. Treatment (cauterisation) is available but often unnecessary, as it resolves on its own once the hormonal trigger is removed.

Vaginal dryness. Without enough lubrication, friction can cause small tears in the vaginal walls or at the entrance. This is common during perimenopause and menopause (when oestrogen levels drop), while breastfeeding, or as a side effect of certain medications. Lubricants help in the short term. If the dryness is oestrogen-related, topical oestrogen cream or pessaries are very effective.

Infections. Chlamydia, gonorrhoea and other sexually transmitted infections can cause cervicitis (inflammation of the cervix) that bleeds on contact. Thrush and bacterial vaginosis can also irritate the vagina enough to cause bleeding. If infection is the cause, antibiotics or antifungals resolve it, and a sexual health screen can identify it quickly.

Cervical polyps. These are small, benign growths on the cervix that bleed easily when touched. They are harmless but can be removed if the bleeding is bothersome. Removal is a quick procedure done during a routine gynaecology appointment.

Cell changes on the cervix (CIN). Abnormal cells caused by HPV infection can make the cervix more prone to bleeding. This is one reason bleeding after sex is worth investigating: a smear test and, if needed, a colposcopy can identify cell changes before they progress.

Endometriosis. In some cases, endometriosis affecting the area behind the cervix (the pouch of Douglas) causes deep pain during sex and bleeding afterwards.

Trauma. Vigorous sex, first intercourse, or sex after a long gap can cause minor tears that bleed briefly. These settle on their own. Come and see us if the bleeding is heavy or doesn't stop.

When to see a gynaecologist

A single episode of light bleeding after sex is usually nothing to worry about, particularly if there is an obvious cause (dryness, vigorous sex, first time with a new partner).

Come and see us if:

• The bleeding happens more than once.
• You are bleeding between periods as well as after sex.
• You have any bleeding after menopause (postmenopausal bleeding should always be investigated).
• The bleeding comes with pelvic pain.
• You have unusual discharge alongside the bleeding (our guide to normal vs abnormal vaginal discharge explains what to look for).
• You are overdue for a smear test.
• You are over 40 and this is new.

If it keeps happening, book an examination sooner rather than waiting to see. The most likely cause is something benign, and an examination is how we confirm that.

What the investigation involves

A gynaecological assessment for bleeding after sex is straightforward and typically includes:

• A visual examination of the cervix using a speculum (the same as a smear test).
• A cervical smear if you are due one, or if the cervix looks inflamed or abnormal.
• Swabs for infection if STIs are suspected.
• A pelvic ultrasound if the bleeding could be coming from higher up (the womb or ovaries).
• A colposcopy if the cervix has visible changes that need closer examination.

Most of this can be done in a single appointment at our clinic. If you are seen by Dr Naoum, Consultant Gynaecologist, the examination, smear and ultrasound can all happen on the same day. Ask for the ultrasound when you book so it can be arranged.

Postcoital bleeding and cervical cancer

This is the concern most women have when they search for this topic, so it is worth addressing directly.

Cervical cancer is a possible but uncommon cause of bleeding after sex. The vast majority of postcoital bleeding is caused by cervical ectropion, dryness or infection. The NHS does list it as a symptom of cervical cancer, which is why investigation is recommended.

Investigation is there to settle the question. It rules out the rare serious cause and identifies the common, treatable one, and a smear test and examination do this quickly.

If you are up to date with your cervical screening and your last result was normal (HPV negative), the chance of cervical cancer causing your symptoms is extremely low. If you are overdue, getting screened is the single most useful thing you can do.

When the blood is coming from somewhere else

Occasionally the bleeding comes from the urethra (urinary tract) rather than the vagina, particularly if you also have urinary symptoms. A urinary tract infection or urethral irritation can look like bleeding after sex. Your doctor can tell the two apart during the examination.

Less commonly, rectal bleeding is mistaken for vaginal bleeding. If the blood appears when you wipe after using the toilet, rather than during or straight after sex, the source may be haemorrhoids or an anal fissure.