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 not dangerous. It is more common in women on the combined pill or who are pregnant, because oestrogen encourages these cells to migrate outward. Treatment (cauterisation) is available but often unnecessary, as it resolves on its own when the hormonal trigger is removed.

Vaginal dryness. Insufficient lubrication causes friction, which can lead to 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 cause vaginal irritation that leads to bleeding. If infection is the cause, treatment with antibiotics or antifungals resolves it. A sexual health screen can identify the infection quickly.

Cervical polyps. 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 postcoital bleeding should be investigated: 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. This is self-limiting and not a cause for concern unless the bleeding is heavy or does not stop.

When to see a gynaecologist

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

You should get checked 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 is accompanied by pelvic pain.
• You have unusual discharge alongside the bleeding.
• You are overdue for a smear test.
• You are over 40 and this is new.

Do not wait and see if postcoital bleeding keeps happening. The most likely cause is something benign, but the only way to confirm that is with an examination.

What the investigation involves

A gynaecological assessment for postcoital bleeding 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 these investigations can be done in a single appointment at our clinic. If you are seen by Mr Naoum, Consultant Gynaecologist, the examination, smear, and ultrasound can all happen on the same day.

Postcoital bleeding and cervical cancer

This is the concern most women have when they search for this topic, and 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. However, postcoital bleeding is listed as a symptom of cervical cancer by the NHS, which is why investigation is recommended.

The purpose of investigation is not to alarm you. It is to rule out the rare serious cause and identify the common, treatable one. 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 bleeding after sex is not a gynaecological issue

Occasionally, the bleeding is coming from the urethra (urinary tract) rather than the vagina, particularly if you also have urinary symptoms. A urinary tract infection or urethral irritation can cause what looks like postcoital bleeding. Your doctor can distinguish between the two during examination.

Rectal bleeding mistaken for vaginal bleeding is also possible, though less common. If the blood appears when you wipe after using the toilet rather than during or immediately after sex, the source may be haemorrhoids or an anal fissure.