What is cervical screening?

Cervical screening can find changes to the cells in your cervix early on. Finding these changes earlier can help prevent cancer developing.

Cervical screening is available for all women between certain ages who are registered with a GP. The ages that women are offered cervical screening depend on where you live in the UK. Your GP can tell you what these ages are. Women are usually invited for screening every three years.

The test involves your doctor or nurse taking a sample of cells from your cervix. This procedure is called liquid-based cytology or cervical smear. These cells are then looked at in a laboratory.

Regular cervical screening is the best way to find early changes to the cells in the cervix. Sometimes, cell changes can be missed. Despite this, cervical screening can prevent cancer in most women.

Even though screening is very effective, you should always see your GP if you notice any unusual symptoms. For example, if you bleed after sex or between periods. If you’ve never been sexually active or never had penetrative sex, screening is still recommended.

Cervical screening and cancer

Cervical screening and cancer

Cervical screening is a way of detecting early changes to cells of the cervix. It’s not a test for cancer. But it can help prevent cervical cancer by identifying early abnormalities that could become cancer if left untreated.

The first step in cervical screening is to take a sample of cells from the cervix using a method known as liquid-based cytology. This is often referred to as a cervical smear.

NHS cervical screening (cervical smear tests)

In the UK, the NHS provides a cervical screening programme for all women who are registered with a GP. The ages when women are invited to attend, and how often screening takes place, varies slightly between the four countries.

In England, Wales and Northern Ireland:

  • women are sent their first invitation for routine cervical screening at the age of 25
  • women between the ages of 25–49 are invited for cervical screening every three years
  • women between the ages of 50–64 are invited for screening every five years.

In Scotland, cervical screening is offered every three years to women aged 20–60.

Once women reach the age of 60–65 (depending on the country they live in), they are no longer invited to have cervical screening unless they’ve had recent cervical changes or haven’t been screened since they were 50. The reason for an upper age limit is because if the cells in the cervix are normal at this time, it’s very unlikely that a cancer will develop in later years. However, women aged 60 and over who’ve never had a screening test are entitled to have one.

Women under 25 (20 in Scotland) aren’t routinely screened as part of the screening programme because changes in a young woman’s cervix are quite normal. In this situation, screening may lead to unnecessary treatment. Research has also shown that screening women in their early 20s isn’t very effective at preventing cervical cancer.

Women who have never been sexually active have a very low risk of developing cervical cancer. However, although their risk is very low, there’s still a small possibility of cervical cancer so screening is still recommended. If you’ve never had sex you may choose not to be screened, and your GP or practice nurse can discuss this with you further.

Women who are no longer sexually active, but who were in the past, are still recommended to be screened when invited. This also applies to women who’ve been vaccinated against human papilloma virus (HPV). Women who’ve never had penetrative sex and women in same-sex relationships are also advised to be screened as they may still have been exposed to HPV.

Women of any age, who’ve had treatment for abnormal cells on the cervix within the last 10 years, may need to have a screening test more often. Your GP can discuss this with you.

Where to go for your screening test

You’ll be sent a letter from your local primary care support service or GP asking you to make an appointment for your screening test. Most women choose to have the test done by their practice nurse or GP. You can ask to have it done by a female doctor or nurse if you prefer.

Cervical screening tests can also be done at a family planning clinic, Well Woman clinic, sexual health clinic or a genitourinary clinic. NHS Direct can give you details of your local clinic. Screening tests can also be done at private clinics.

Can cervical screening prevent cancer?

For most women, cervical screening can prevent cancer. The cervical screening programme isn’t 100% effective, but regular cervical screening every 3–5 years is the best way to detect changes to the cells of the cervix. Almost half of the women who develop cervical cancer in the UK have never had a cervical screening test.

How cervical screening can prevent cancer

How cervical screening can prevent cancer

Find out how regular cervical screenings (smear tests) can prevent cervical cancer.

About our cancer information videos

How cervical screening can prevent cancer

Find out how regular cervical screenings (smear tests) can prevent cervical cancer.

About our cancer information videos

Benefits and difficulties of cervical screening

The main benefits and difficulties are explained here:


  • Cervical screening reduces the risk of developing cervical cancer.
  • The number of women who develop cervical cancer has halved since the 1980s due to most women regularly having cervical screening.
  • Cervical cancer is now an uncommon illness in the UK due to regular screening.
  • NHS cervical screening saves around 5,000 lives a year in England.


  • Cervical screening can show minor changes that may go back to normal on their own, but knowing they are there can be worrying.
  • Sometimes, too few cells are taken or the cells can't be seen properly and the test will need to be done again.
  • Regular cervical screening can prevent cancers from developing, but it doesn't prevent every case.
  • Cervical screening doesn't pick up every abnormality of the cervix.
  • Some women find the test an unpleasant experience.

Reliability of cervical screening

Cervical screening, like other screening tests, isn't perfect. So it is not always possible to detect early cell changes that can lead to cancer.

Abnormal cervical cells in your sample may not be recognised because:

  • sometimes they don't look very different from normal cells
  • there may be very few abnormal cells in the sample.

Occasionally, a test will have to be taken again because:

  • there may not have been enough cervical cells in your sample to give an accurate assessment
  • the sample may not have been properly prepared
  • the container your sample was put in may have been broken.

Although every effort is made to ensure the screening programme works properly, very occasionally mistakes happen.

In recent years, the cervical screening programme has been improved so that mistakes are far less likely. All screening samples are now checked by two technicians so that the chance of missing an abnormality is greatly reduced.

Cervical screening is very effective at picking up early changes, but you should see your GP if you have any unusual symptoms, such as bleeding after sex or between periods. If you have symptoms, you may need to be referred for tests.

What happens to test samples once they've been looked at?

The laboratory that looks at your sample will keep it for at least 10 years. Your latest result can then be compared with the ones you've had before. This is to make sure you get the treatment you may need. All screening records, including your samples, can be looked at again (reviewed) if needed.

On the rare occasion that a review shows you should have been cared for differently, you'll be contacted. For more details about NHS record keeping you can contact NHS Direct.

Back to Cervical screening

The cervix

The cervix is the lower part of the womb (uterus). It’s often called the neck of the womb.

Preparing for having a cervical screening test

A cervical screening test is a very simple procedure and takes less than five minutes.

Getting your cervical screening results

You should get your results within about two weeks of having your cervical screening test.

Your feelings about cervical screening

People react differently to their screening results. There is no right or wrong way to feel.

Cervical intra-epithelial neoplasia (CIN)

Cervical intra-epithelial neoplasia (CIN) is a term used to describe changes in the surface (squamous) cells of the cervix.

Diagnosing CIN

A colposcopy is used to confirm whether you have cervical intra-epithelial neoplasia (CIN) and how severe it might be.

Grading CIN

Knowing the grade of CIN will help your specialist plan the best treatment for you.

Treating CIN

If you have been diagnosed with CIN, you may have treatment to remove the abnormal cells. There are different types of treatment.

After treatment for CIN

Most women feel fine after treatment for CIN but some may feel unwell for a few hours. You will be referred for regular screening tests.