Cervical Screening (Cervical Smear Test)

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Women are routinely invited to have cervical screening tests (also called smear tests). The tests are done to prevent cervical cancer, not to diagnose cancer. During each test some cells are removed from the neck of the womb (cervix), with a plastic brush. The cells are examined under a microscope to look for early changes that, if ignored and not treated, could develop into cancer of the cervix. You are very unlikely to develop cervical cancer if you have regular cervical screening tests at the times advised by your doctor. If the test shows any abnormality, you will have treatment to stop you ever getting cancer of the cervix. So, an abnormal test does not mean you have cancer. It means you should have some treatment to stop you getting cancer.

Diagrams showing uterus and cervix

The cervix is the lowest part of the womb (uterus). It is often called the neck of the womb. It is inside a woman's vagina. If you were to put a clean finger into your vagina as far as it will go, you might be able to feel your cervix deep inside.

You will be asked to remove your clothing from the waist down. If you wear a loose skirt, you may only need to remove your knickers. You will be asked to lie on your back on the examination couch. You should bend your knees, put your ankles together, and let your knees fall open. A doctor or nurse will put an instrument called a speculum into your vagina. The speculum is put in while it is shut. The doctor or nurse then gently opens it. This opens the vagina and allows the cervix to be seen (at the top of the vagina). The doctor or nurse then uses a thin plastic stick with a small brush at the end to gently scrape some cells from the surface of the cervix. The cells that are obtained on the brush are sent away to be examined in the laboratory.

vaginal speculum and cervical brush


The sample taken from your cervix is put into some liquid to be sent to the laboratory for testing. At the laboratory the liquid is spun to get rid of any extra cells such as blood cells or mucus. The cells from your cervix are then put on a slide and examined under the microscope. In some cases the same sample may be tested for a virus called human papillomavirus (HPV) which is known to cause cancer of the cervix.

Cervical cancer is a disease that can often be prevented. Early changes can be detected in the neck of the womb (cervix), which indicate that cancer may develop. Since screening started, the numbers of cases of cervical cancer have dramatically dropped, and so have the number of women dying from it. Cancer of the cervix is now only the seventeenth most common cancer in women in the UK, whereas across the world it is the third or fourth most common cancer. This is because of the screening programme. It is one of the few types of cancer which can be detected and stopped before it ever begins.


In most women the cells that are taken are found to be normal. Abnormal cells are found in some women. An abnormal result does not mean cancer in the vast majority of cases. Abnormal cells indicate that cancer may develop sometime in the future. About 6 women in 100 will have an abnormal result that requires further testing or treatment. Most of these changes will not lead to cervical cancer. Treatment can be given to prevent cancer from developing in women with abnormal cells.

The NHS Cervical Screening Programme invites all women for regular tests automatically. You need to be registered with a GP, as this is how the programme obtains your name. It is therefore important that your GP has correct address details for you.



  • First invitation for screening in England, Wales and Northern Ireland is at age 25. It is age 20 in Scotland.
  • Routine recall (repeat screening test):
    • England, Wales and Northern Ireland: three-yearly tests from age 25 to age 49. Five-yearly tests from age 50 to 64. Screening stops at age 65.
    • Scotland: three-yearly tests from age 20 to age 60.
  • Women over 65 years of age should be screened if:
    • A recent cervical screening test has been abnormal.

Cervical cancer is not uncommon. In recent years the number of cases has fallen due to cervical screening tests. However, there are still around 3,000 new cases of cervical cancer diagnosed each year in the UK. Most of these occur in women who have never had a screening test, or who have not had one for many years. Cervical cancer can be prevented if you have regular screening tests. It is estimated that over 4,000 women are prevented from developing cervical cancer every year in the UK, due to cervical screening.


The results are reported as one of the following:

  • Normal.
  • Inadequate.
  • Abnormal - of which there are several grades or degrees of abnormality:
    • Borderline.
    • Mild abnormalities in the cells of the neck of the womb (cervix): mild dyskaryosis.
    • Moderate abnormalities in the cells of the cervix: moderate dyskaryosis.
    • Severe abnormalities in the cells of the cervix: severe dyskaryosis.
    • Possible cancer cells: invasive or glandular neoplasia.

The test may also look for human papillomavirus (HPV). This is a type of wart virus that can be passed on by having sex. It is involved in the development of most cases of cervical cancer. However most infections with HPV will clear completely from the body within two years. This means that most women who are infected with HPV do not develop cancer.

Normal result


No screening test is 100% accurate. Some tests will be falsely reassuring (so-called false negative results) - where the test is reported as normal but an abnormality is present. This is why it is important to have tests regularly. Cervical cancer takes years to develop from the earliest abnormalities. Therefore, there should be plenty of opportunity to detect abnormalities before problems do develop. (It is also possible to have false positive results. This means that a result is incorrectly labelled as abnormal. This can cause a lot of worry, but usually a colposcopy examination - see below - will reveal that things are normal.)

Inadequate test


Abnormal result

About 6 in 100 tests are reported as abnormal. There is a range of changes that may occur. In nearly all cases, these changes do not mean cancer.


Depending on the degree of abnormality (and the HPV test if it is done), women with abnormal results may:

  • Need nothing further other than normal recall for another smear in the normal 3-5 years.
  • Be referred to a gynaecologist or to a colposcopy clinic for further examination of the cervix. Depending on the result of this examination, treatment may or may not be needed.



Moderate or severe dyskaryosis shows up in even fewer women. About 1 in every 100 smear tests shows either one of these abnormalities. If your test shows moderate or severe dyskaryosis it is still very unlikely that you will have cervical cancer. The main difference is that these changes are less likely to return to normal by themselves. You will probably need some treatment and this will happen at colposcopy.

Invasive or glandular neoplasia is a more serious abnormality which shows in less than 1 test in 1,000. Neoplasia means new growth of cells. Invasive neoplasia suggests cervical cancer might be present. This is not proven until a sample of cervical tissue (a biopsy) has been taken at colposcopy. Glandular neoplasia is another significant abnormality that can be seen on cervical screening. It suggests that there is an abnormality in the lining of the womb (the endometrium), rather than on the cervix. This is because glandular cells (found lining the womb) are different to the ones normally found on the cervix. Glandular neoplasia again does not necessarily mean cancer, but cancer needs to be excluded. You will probably need to have a colposcopy and may need to have a small camera passed into the womb (called hysteroscopy).

It is important to remember that it is rare for cervical cancer to be found on cervical screening. Screening is designed to find early changes that could become cancer in the future, if left untreated.

Human papillomavirus (HPV)

Some samples are also tested for the presence of HPV. This varies depending on where you live. Currently in England and Northern Ireland, if your test shows borderline or mild abnormal changes, the same sample will automatically be tested for HPV. If this is negative, your chances of developing cervical cancer are so tiny, you can go back to your normal three- or five-year recall without extra tests. In Scotland and Wales, if you have borderline or mild abnormal changes, you will have a repeat smear after six months or be referred for colposcopy (see below).

Across the UK, if you have had treatment for abnormal cells after an abnormal smear, your next smear test will be automatically tested for HPV. Knowing whether HPV is present or absent helps to determine how you should be treated and screened from that point on. This test - the combination of the smear looked at under the microscope with the HPV test - is called a "test of cure".

The reason for HPV testing becoming increasingly important is that over 99 in 100 cases of cancer of the cervix are caused by HPV. Therefore, if it is not present, the chances of getting cancer of the cervix are vanishingly small. This is also the reason why since 2008 in the UK, school-aged girls are vaccinated against HPV. It is hoped, as time goes by, this will further reduce the numbers of people with cancer of the cervix. As more studies are done, it is likely that testing for HPV will change across the UK.



The laboratory that reports the cervical screening results will determine whether you need to be referred for colposcopy (based on the current result and your past results). Either the laboratory will refer you directly to colposcopy, or they may ask your GP to make this referral. You should contact your GP if you have any questions or worries about your result, or the colposcopy examination (although you would usually be sent an information leaflet too).

See separate leaflet called Colposcopy for more information.

Yes. A minor abnormal change often goes away by itself. This is why a repeat test after 3-12 months may be all that is needed. If the cells remain abnormal, or the changes are more marked, treatment is offered. This will stop cancer from developing in the future. Treatment, if needed, is simple and almost 100% effective. Treatment is done at the colposcopy session. Abnormal cells are removed or destroyed by freezing, burning, laser or cutting them away.

Cervical screening is going through some exciting changes. It is hoped that new developments will mean in the future even fewer women develop cervical cancer. The nationwide roll out of the HPV vaccine, which began in 2008, should reduce cases significantly. The use of HPV testing as part of the smear process is becoming more widespread. This is improving the accuracy and efficiency of the smear programme. Studies are being done to see if just testing HPV could be used to prevent cervical cancer. Some have studied how effective it is if women take their own samples from the vagina. Even better, HPV in the neck of the womb (cervix) can be detected from a sample of urine. If this could be used as a screening process, it would be much easier than having a smear taken. There are studies going on to see if this could be used as a reliable screening test in the future.

How effective is the cervical screening test?

It is estimated that the cervical screening test can detect and prevent three quarters of all cases of cervical cancer. This means that for every 100 women who would have developed cancer of the neck of the womb (cervix), about 75 cases can be prevented. So, although it does not detect an abnormality every single time one occurs, overall it is a reliable test.



See separate leaflet called Human Papillomavirus (HPV) Immunisation for more information and also the leaflet dealing with cervical cancer. You may decide that you do not want to have a test if you have never had sex.

I am a lesbian. Do I need a cervical screening test?

Yes. If you are a lesbian, you are still advised to have cervical screening. This is because there is still a risk of cervical cancer, and HPV can still be transmitted between partners. Additionally, some lesbian may have had sexual contact with a man in the past.


This depends on the type of hysterectomy, and why it was done. Your doctor will advise you on this. In general, if you have a total hysterectomy - removal of the womb (uterus) and cervix - for a reason not due to cancer, you no longer need cervical screening tests. Some types of hysterectomy leave the cervix (called subtotal hysterectomy), and some are done to remove a cancer. In these situations, a test of the cells of the remaining cervix, or of the top of the vagina (called the vault), may still be advised.

Does the cervical screening test really save lives?

Yes. By studying the statistics of cancer cases since the tests began it is estimated that up to 4,500 cases of cervical cancer are prevented each year in the UK. After screening was introduced, the number of cases of cervical cancer each year dropped by almost half.

Wouldn't it be better to have yearly tests?



Why aren't women in England, Wales and Northern Ireland called from age 20?



It is really important that women in England, Wales and Northern Ireland (especially sexually active women) do not miss their first invitation for cervical screening at age 25. Otherwise, there is the potential (especially if the woman has been sexually active since her teenage years) for abnormalities in the cervix to become more serious. So, the main risk of starting the screening programme at age 25, is that some women might miss their first invitation. However, since this was changed, initially in England, experts have been following up the effect. There has not been a rise in cancers in this age group, so it seems safe. Scotland plan to change to start screening from age 25 in 2016.




Can I have cervical screening when I am pregnant?

If you are due your routine cervical screening test and you are pregnant, this should be put back until after your baby is born. Usually, it is advisable to wait until at least 12 weeks after your baby is born. This gives the cervix a chance to recover from pregnancy and childbirth. Tests performed earlier are more likely to be inadequate.




Note: if you get any of the following symptoms, you should see your GP:

  • Bleeding after having sex (called postcoital bleeding).
  • Bleeding between periods (called intermenstrual bleeding).
  • Bleeding after the menopause (called postmenopausal bleeding).

A little bit of light bleeding or spotting for up to a day after having a smear test may sometimes happen, and is normal.

I am a transgender man - do I need cervical screening?




Does being immunosuppressed increase my risk of cervical cancer?

Yes - women who are immunosuppressed are at an increased risk of having changes that may become cancerous. Immunosuppressed means your immune system doesn't work well. This may be because of certain diseases or medicines. The main groups affected are:

  • Women who have had a kidney transplant. Also women who have kidney disease which is severe enough to require dialysis. These women should have a smear and/or colposcopy done as soon as possible after the decision for transplant or dialysis has been made. However, it is not recommended that these women have more frequent cervical screening - just that early referral to colposcopy is advisable with any abnormal screening results.

Women taking cytotoxic medicines for rheumatological disorders, immunosuppressive medicines after other transplants, chemotherapy for cancer, steroids or tamoxifen have not been shown to be at increased risk. They should, however, have regular screening in line with their age group.

Original Author:
Dr Tim Kenny
Current Version:
Peer Reviewer:
Prof Cathy Jackson
Document ID:
4213 (v46)
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