Post-coital bleeding is when a woman experiences vaginal bleeding after having sex. If you experience vaginal bleeding and it is not due to your period, see your doctor. Normally it is nothing to worry about but, in some cases, it could be a sign of something more serious.
What is post-coital bleeding?
Post-coital bleeding is vaginal bleeding that occurs within 24 hours after sexual intercourse.
Normally a woman should only have vaginal bleeding when she has a period, but if a woman has irregular periods she may not be sure if the bleeding is normal or not. If you are not sure if your bleeding is part of a period, see your GP to discuss this.
Heavy bleeding immediately after sex is not normal – seek urgent medical help
Where does post-coital bleeding come from?
A woman's reproductive system can be divided into the upper part and lower parts:
- The upper part includes the body of the uterus, the fallopian tubes and the ovaries. Bleeding during a woman's period occurs when the lining of the uterus breaks down as part of a normal monthly cycle.
- The lower part of a woman’s reproductive system is the neck of the womb (or cervix), the vagina and the outer part which is called the vulva and labia.
It is the lower parts which are usually involved in post-coital bleeding.
What are the causes of post-coital bleeding?
The most common causes of post-coital bleeding include:
- Cervical polyps – small growths caused when cells multiply abnormally. In rare situations these can develop into cancer. They can easily be removed at the time of a smear test.
- Cervical ectropion – when cervical cells grow outside the cervix, where they can be damaged during sex.
- Vaginal thrush – a common yeast infection that can occasionally cause bleeding along with other common symptoms such as pain, itching and vaginal discharge.
- The contraceptive pill or injection – contraceptives can affect the lining of the cervix and make it extra-sensitive, especially when you first start on them.
- Having sex – occasionally, sex can cause bleeding from a woman's vagina or vulva, especially in women with a condition called atrophic vaginitis where the lining of the vagina becomes thinner.
Less common but more serious causes include:
- Cervical cancer – this a serious condition, however, if treated early it can be cured completely. This cancer can be identified before it becomes a serious threat by having a smear test. Remember that no test is perfect, so even if you have had a recent smear test, you should still see your GP if you have post-coital bleeding.
- Cervical infections – such as chlamydia and gonorrhoea. These infections can cause serious problems and need to be treated.
- Pregnancy – bleeding in early pregnancy is common, but needs to be checked out by a doctor. Early pregnancy bleeding can occur with an ectopic pregnancy, which occurs when the pregnancy is growing in the fallopian tube. This is potentially very dangerous.
In girls who have not started having periods, any vaginal bleeding is not normal. See your doctor for a check-up and advice.
Read more about these causes of post-coital bleeding
How is post-coital bleeding diagnosed?
To find out the cause of the bleeding, your GP will need to ask you some personal questions about your sexual activity. These questions can be a bit embarrassing but remember your GP deals with this kind of thing all the time. The more information you can give the easier it will be for them to find out what's going on.
Your GP will also need to find out about:
- what contraception you are using
- any other medications you are on
- when you last had a cervical smear.
If you are not seeing your regular GP it can be really helpful if you take along your medications such as “the pill” if you are using it.
Tests and procedures
There are some common tests and procedures which your doctor may also require, such as:
- A urine sample to check for pregnancy or urine infection.
- A vaginal examination to look for causes of bleeding in your vagina or cervix. This examination is the same as having a smear test. A smear might be repeated and tests for infection can be done at the same time.
- Occasionally your GP may also do a test called a pipelle. This is done at the same time as a smear test, but using a very thin plastic tube to collect a sample of the lining of the uterus. The GP will want to know if you are pregnant before this test.
- An ultrasound scan, especially if: your pregnancy test is positive; the examination suggests there is a problem with your uterus or ovaries; you are over 45 years old or if there is a family history of certain types of cancer.
What is the treatment for post-coital bleeding?
Treatment for post-coital bleeding will depend on what the cause is. Your doctor will advise you on the best course of action once a diagnosis has been made.
Wan YL, Edmondson RJ, Crosbie EJ. 2015 Intermenstrual and Postcoital Bleeding. Obstetrics, Gynaecology And Reproductive Medicine 25:4 107-12
Common causes of post-coital bleeding
Polyps occur when some cells in an area grow too much. They can occur in many parts of the body and are usually not serious. Because a polyp is made of cells which have grown abnormally, they can occasionally develop into a cancer. This is how many bowel cancers are thought to start.
Cervical polyps often occur in women with polyps inside the uterus. If the polyps grow too much they can bulge out of the opening of the cervix, into the vagina. The cells on polyps are not tough like skin, so if they are rubbed during intercourse they will bleed.
Rarely, cervical polyps develop into cancer of the lining of the womb, called endometrial cancer. Endometrial cancer is not usually detected on a cervical smear but does usually cause irregular vaginal bleeding before it is very advanced and so there is a good chance of cure. Read more about cervical polyps.
This condition is not serious but is one of the more common causes for post-coital bleeding. Sometimes female hormones cause the cells inside the cervix to grow outward into the part of the cervix which your doctor and nurse can see when they take a cervical smear. This is why sometimes a woman may have some bleeding after a smear.
Cervical ectropion is similar to cervical polyps except that the cells have not grown too much and are not abnormal, they are just in the wrong place on the outside part of the cervix, where they can be damaged during sex. Read more about cervical ectropion.
Occasionally a bad case of thrush can cause bleeding. Usually, there will be a lot of discharge and discomfort as well. You can buy treatment for thrush over the counter at a pharmacy. If you treat thrush but the bleeding doesn’t go away or if you get thrush often, see your GP for a check-up. Recurrent thrush can be a sign of diabetes. Read more about thrush.
Bleeding due to the contraceptive pill or injection
When you first start taking “the pill” or “the injection” you can have some irregular bleeding for 2 or 3 months. Irregular bleeding when on the injection is quite common and is one of the main reasons why women stop using this form of contraception.
If you are sexually active and are not planning to become pregnant, there are many effective different types of contraception. Go to family planning or your GP to discuss the choices and find a method of contraception that works for you.
Bleeding caused by sex
Occasionally, sex can cause bleeding from a woman’s vagina or vulva. This may occur in some women the first time they have sex but should not be heavier than a period or last more than a couple of days.
Although sexual activity does not usually cause damage to a woman’s vagina, a rip or tear in the vagina can sometimes occur. The vagina has a lot of blood vessels just under the surface, so the bleeding can be very heavy and will require management in a hospital.
Bleeding from the vagina after sex is more common in women who have gone through the menopause and stopped having periods.
- This is often associated with a condition called atrophic vaginitis where the lining of the vagina becomes thinner and more susceptible to infection.
- Women on medications for breast cancer (such as tamoxifen) may also have this condition due to low hormone levels.
Using a water-based lubricant during sex can help prevent bleeding if this is the cause.
Read more about menopause.
Less common but more serious causes of post-coital bleeding
Cervical cancer is a serious condition, however, if treated early it can be cured completely. Fortunately, this cancer can be identified before it becomes a serious threat by having a smear test.
The cervical smear test is a very effective way of preventing cervical cancer. The chances of getting cervical cancer if a woman has regular smears is very very low.
However, no test is perfect, so even if you have had a recent smear test, you should still see your GP if you have post-coital bleeding.
Read more about cervical smears and cervical cancer.
Infection of the cervix is usually a sexually transmitted disease. Some of these such as chlamydia and gonorrhoea are serious and need to be treated. The infection can spread from the cervix to the uterus and fallopian tubes and cause problems getting pregnant. They are also sexually transmitted diseases so your sexual partner will also need to be checked for infection.
Condoms are a very effective protection against infections such as chlamydia and gonorrhoea. They also protect against pregnancy and serious conditions such as HIV.
Bleeding in early pregnancy is common. Most women will know they are pregnant soon after they miss a period, but many women will not realise they are pregnant for a couple of months. If early pregnancy bleeding occurs around the time a woman is expecting a period, it is easy to mistake this for a period.
There are several reasons why it is important to find out if you are pregnant:
- If you are pregnant and plan to continue the pregnancy you may need to change your lifestyle (smoking or alcohol) to make sure your baby gets the best possible start in life.
- The treatment of bleeding in early pregnancy is very different to treatment of post-coital bleeding
- Your GP may not want to prescribe some medications if you are pregnant.
- Early pregnancy bleeding can occur with an ectopic pregnancy, which occurs when the pregnancy is growing in the fallopian tube. This is potentially very dangerous.
Read more about pregnancy.
|In girls who have not started having periods any vaginal bleeding is not normal. See your doctor for advice.