Why am I bleeding after sex?

Bleeding after sex can be confusing and distressing, and seeing any blood when you know your period isn’t due can also cause anxiety. However, there are many benign reasons as to why it can occur. Many people go to their doctor with this problem, and most of the time the cause isn’t anything serious.

Bleeding after sex is also known as postcoital bleeding, and this is bleeding which occurs after intercourse which is not related to menstruation. Up to approximately 9% of people who menstruate experience postcoital bleeding.¹ In 50% of people, their bleeding did not occur again after the initial episode when they were asked two years later.² A third (30%) of people who have postcoital bleeding also experience dysfunctional uterine bleeding (such as heavy periods or bleeding between periods).³

To determine the cause of the bleeding, your GP or gynaecologist will usually ask questions about pain, the amount of bleeding you are experiencing, the colour of the blood, and the timing of the bleeding in relation to intercourse.

Although the amount and colour of blood seen can vary significantly between individuals with the same underlying cause, bleeding with or without pain can help determine what is going on.

Causes of bleeding after sex with accompanying pain

There are many causes of painful sex (either during sex or after) and bleeding. Loss of virginity is a normal cause of pain and bleeding. The hymen, the thin membrane that partially covers the opening of the vagina, can bleed if it gets torn or stretched when you have penetrative sex for the first time. However, while some will experience bleeding, others will not, and both instances are perfectly normal. The membrane is not vascular (i.e. it doesn’t have a lot of blood vessels), so the bleeding should be light and not continue for long after intercourse.

Trauma to the vagina

Pain and heavy bleeding can occur after trauma. For example, vigorous sex or the use of toys can lead to cuts in the vaginal wall. The blood in this instance is usually bright red and can look like a light period. If the cut is large, which can only be assessed if you see a doctor, then the blood can also come out in clots, particularly if you have been lying down and then get up.

Sometimes the bleeding point may need to be cauterised, which is a medical technique for closing off bleeding points. The pain will be different to that of period pain, and will be sore rather than cramps. If you have to change a pad every hour or are getting lightheadedness with moderate bleeding you should go to hospital and get checked out straight away.

Infection

Pain and bleeding can also be caused by infections, such as pelvic inflammatory disease (PID) or cervicitis (inflammation of the cervix). These are usually caused originally by sexually transmitted infections and can cause pain during sex, particularly at deep penetration. Bleeding occurs as the tissues are inflamed and friable (easily irritated).

In this case the bleeding is likely to be light red or brown, seen on wiping or on a pad, and it may also have a bad smell. PID can also cause heavy periods and bleeding between periods, and is usually associated with pus in discharge. If you have cervicitis, discharge would be more watery.

Endometritis (inflammation of the lining of the womb) can also lead to postcoital bleeding, although this is not usually the primary symptom. Endometritis (not to be confused with endometriosis) can be caused by infectious agents such as chlamydia, gonorrhoea, bacteria entering the uterus after childbirth, surgical procedures, or IUD placement, but also by foreign bodies or polyps, and can cause heavy periods or bleeding between periods.

Vaginitis

Vaginitis (inflamed vaginal walls as the result of an infection or hormonal imbalance) and vaginal atrophy/atrophic vaginitis (when the walls of the vagina have thinned which usually occurs when there is a loss of oestrogen, as in postmenopause or in those breastfeeding, for example) can also cause pain and bleeding during sex. Up to 50-60% of postmenopausal people experience atrophic vaginitis.⁴

The pain is usually a soreness experienced during sex and can continue after sex. Some people experience a burning pain. As the vaginal walls are inflamed, they are more likely to bleed during sex.

A reduction in vaginal secretions in the above situations results in friction during intercourse which can irritate the vaginal walls and cause bleeding. The blood is usually light red, seen on wiping or on your underwear. Urinary frequency, urgency, and burning can also be present during postmenopause.

Prolapse

Pelvic organ prolapse (when the cervix, bladder, uterus, or rectum come down into the vagina and maybe beyond due to weak pelvic floor muscles) can lead to trauma and irritation of the cervix and/or vagina. Sex can be uncomfortable or sore, which can continue after sex, and bleeding can occur, usually light red.

Pelvic organ prolapse has varying degrees of severity, and in some cases, you can feel the cervix or uterus at the opening of the vagina. It can also be seen prolapsing out through the vagina. Other symptoms include urinary urgency, stress incontinence and feeling a heavy/dragging sensation down below.

Causes of bleeding after sex without accompanying pain

Polyps (benign growths) from the endometrium or the cervix can result in postcoital bleeding due to trauma of the tissue during intercourse. They are the most common benign growth, occurring in 2-5% of people with wombs.⁵ They can grow up to 1-2cm in size and are friable, so bleed easily. The bleeding is usually light red and seen on wiping, with small amounts seen on underwear.

Polyps can be seen on speculum examination by your doctor and can be removed easily during an appointment. Most polyps are not cancerous, but, if removed, they are always sent to the laboratory to be analysed. Polyps that grow from the endometrium can protrude out of the cervix which can cause the same symptoms for the same reasons.

A cervical ectropion is when the glandular cells that cover the lining of the inside of the cervix are exposed on the outer surface of the cervix. It is very common and often occurs in adolescence, in people taking oral contraceptive pills, and in pregnancy. The glandular cells are vulnerable to trauma and will bleed if touched during sex. No pain is caused but spotting (usually light red) can occur.

Cancer

The cause of postcoital bleeding that creates the most fear is cervical cancer. For those with a cervix, cervical cancer is the fourteenth most common cancer in the UK.⁶ Most cases are diagnosed in people aged 30-34.⁷ The main risk factors are having HPV (human papillomavirus), smoking, and having a weak immune system. Again, cancer cells are friable and bleed easily, so sex can result in bleeding but is usually painless. Small amounts are seen on wiping, light red in colour or brown.

It is important to attend your smear test, and HPV testing can be done at the same time. Attending your smear test is the best way to prevent cervical cancer or to monitor any abnormal cells. Smear tests are good at picking up any suspicious lesions early if you attend regularly (every 3 years in the UK from 25 years).

Vaginal cancer can also be another cause of bleeding, although vaginal cancer accounts for less than 1% of all new cancer cases in women in the UK, so is rare.⁸ It usually doesn’t cause any obvious symptoms, but people have reported postcoital spotting and unusual vaginal discharge.⁹

Postcoital spotting can also, rarely, be a symptom of endometrial cancer. This is more likely to occur in people between the ages of 40 to 74 years who have gone through menopause.¹⁰ Usually, people experience brown spotting or bleeding similar to the start of a period (even though they have gone through menopause, which is why it is so shocking when it occurs), as opposed to postcoital bleeding specifically. In postmenopausal people, vaginal dryness is more likely to be the cause.

What will happen if you go to the doctor with postcoital bleeding?

If you present to your doctor with postcoital bleeding, they will take a history and examine you using a speculum. The speculum allows the doctor to visualise the cervix and vaginal walls clearly and swabs are usually taken to check for any infection.

A manual exam is usually done, particularly in those who have reported pain, so that the doctor can check what is causing the pain. It is also done to check for any lumps, and lymph nodes are also felt. Any lesions on the cervix will usually lead to a referral to a colposcopy which is where a gynaecologist will look at your cervix more closely using a microscope.

With bleeding after sex, the majority of people will have no obvious underlying cause and the bleeding usually disappears. If there is a cause, your doctor will prescribe the right treatment, which may be antibiotics for an infection or removal of a polyp, for example. Any suspicious lesions will be further examined and investigated.

Although it has been mentioned above that in certain conditions you may experience heavy bleeding or light bleeding or a specific colour of blood, it is important to remember that everyone is different, and so you may not experience the exact symptoms stated.

Regardless, it is important to see your doctor if you experience bleeding after sex, particularly if you know that it is not normal for you. If postcoital bleeding is happening often and/or you have not had a smear test as yet, it is even more important to see your doctor.

Smear tests can be done at your GP practice by a doctor or trained practice nurse, or at a sexual health clinic. While it is important to get checked out, most cases of postcoital bleeding clear up themselves without any need for treatment and while it can be scary, it is usually nothing to worry about.

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Last updated October 2023
Next update due 2026