What is cervical screening?

Cervical screening is a way of preventing cervical cancer (cancer of the cervix). It uses tests to find abnormal changes in the cells of the cervix.

The first part of cervical screening is to have a smear test. This is also called the cervical screening test.

We have more information about having a smear test.

Why have cervical screening?

Abnormal cell changes in the cervix are common, and often improve naturally. But sometimes these changes need treatment because there is a risk they may develop into cancer.

Abnormal changes cause no symptoms. You will not know if you have them unless you have cervical screening. Screening finds abnormal cell changes, including the ones that are most likely to become cancer. These cells can then be treated. This is an effective way of preventing cervical cancer.

Who can have cervical screening?

Cervical screening is for anyone who has a cervix. It is important to have, even if you have had the HPV vaccination. The vaccination protects against the most common types of high-risk HPV that cause cervical cancers. But it does not protect against all types.

It is safe to have cervical screening if you are pregnant, but you can usually delay it if you prefer. A screening test (the cervical smear test) during pregnancy may cause a small amount of bleeding afterwards. This is normal and does not affect your baby.

Women

The NHS will contact you when it is time for your cervical screening if you are:

  • 25 to 64 years old
  • registered as female with a GP.

You do not need screening if you have had surgery to remove your cervix. If you have had surgery to the cervix, vagina or womb but you are not sure what your operation involved, your GP can find out from your medical records.

If you are not sure about having cervical screening for any reason, talk to your GP, practice nurse or sexual health service.

Trans and non-binary people

If you are a trans man or non-binary person and have a cervix, you should have screening too. But, you may not be sent an invitation if you are registered as male with your GP. Tell your GP if you want to have cervical screening, so they can arrange regular tests for you.

Jo’s Cervical Cancer Trust (Jo's Trust) has detailed information about cervical screening for trans and non-binary people. This includes information about having a smear test, trans-specific clinics and further support.

You do not need cervical screening if you are a trans woman or were assigned male at birth. The NHS has more information about other types of screening for trans women

HPV and cervical screening

The main risk factor for cervical cancer is an infection called the human papilloma virus (HPV)There are over 100 types of this virus. Some types of HPV can affect the cervix. The types that cause abnormal cell changes in the cervix are called high-risk HPV.

Usually, the body’s immune system gets rid of the infection naturally. There are no symptoms and often the virus does not cause damage. Most people will never know they had it.

In some people, the immune system does not get rid of the infection and the virus stays in the body for longer. We do not know exactly why this is. If the cervix is affected by HPV for a long time, the virus can cause damage that may eventually cause cancer.

HPV is very common, and most people are infected with it at some point. It can affect all sexual orientations and anyone who has ever been sexually active. This includes people in a long-term relationship with one partner. HPV may still affect you even if you have not been sexually active for some years.

The virus can live on the skin around the whole genital area. It passes easily from person to person during any type of sexual contact, including skin-to-skin genital contact, or sharing sex toys. Using a condom or other barrier contraception may reduce your risk of HPV infection, but it does not offer complete protection.

If you smoke

Smoking makes it harder for your body to get rid of an HPV infection. This means that if you smoke you have a higher risk of cervical cancer. If you want to give up smoking, your GP can give you advice.

If you want to stop smoking:

Cervical screening results

Test results in England, Scotland and Wales

In England, Scotland and Wales, your cervical smear sample is tested for high-risk HPV. Samples that show HPV are then checked under a microscope for abnormal cells. Your test result may show one of the following:

  • No HPV

    If you are not infected with HPV, your risk of cervical cancer is very low. You will be offered another cervical smear test in 3 years (or 5 years if you are aged over 50).

  • HPV but no abnormal cells

    If you have HPV but no abnormal cells, you will be offered another cervical smear test earlier than usual. This is to check that your body has got rid of the HPV virus. Your results letter will explain when. Usually the HPV is gone by the next test.

  • HPV and abnormal cells

    If you have HPV and abnormal cells, you will be referred for a procedure called a colposcopy. This finds out more about the cell changes and shows if you need treatment to remove abnormal cells.

  • An unclear result

    This means the laboratory could not get a result from the sample for technical reasons. It is nothing to worry about, but you will need to have the cervical smear test again.

Test results in Northern Ireland

In Northern Ireland, your cervical smear sample is checked under a microscope for abnormal cells. Your test result may show one the following:

  • No changes

    This means your sample showed no abnormal changes to the cells in the cervix. This is also called a negative result. You will be offered another cervical smear test in 3 years (or 5 years if you are aged over 50).

  • Not enough cells to test

    This means there were not enough cells in the sample. You will be asked to have the test again in 3 months.

  • Minor changes

    If your sample showed slight abnormal changes to the cells, it will be tested for high-risk HPV. 

    If you are not infected with HPV, the minor changes are likely to go back to normal on their own. You will be offered another cervical smear test in 3 years (or 5 years if you are aged over 50). 

    If you have an HPV infection, you will be referred for a procedure called a colposcopy. This finds out more about the cell changes and shows if you need treatment to remove abnormal cells.

Changes which require further tests

If your sample shows any other type of change, you will be referred for a procedure called a colposcopy to find out more.

Your feelings about test results

Often, the hardest part of cervical screening is waiting for results. It is natural to worry about this.

Getting an abnormal test result can be stressful. You may find the uncertainty difficult to cope with. And it can be frustrating to find you need more tests or treatment and will have to wait for results again.

It is important to remember that most people who have an abnormal test result will not develop cervical cancer. The aim of screening is to find the small number of people who need treatment to prevent cancer. Research shows that screening tests in the UK are good at this.

Colposcopy

If your cervical smear test shows abnormal cells, you may have a different test to look closely at your cervix. This is called a colposcopy.

During the colposcopy you may:

  • Be offered treatment to remove the abnormal cells

    Sometimes the doctor or nurse doing the test can see that the cells are abnormal. They may offer you treatment to remove these cells during the colposcopy. They will only offer treatment if they are sure the cells are very abnormal, and that there is a risk of cancer developing. If you have questions, or are not sure, the treatment can always be done on another day.

  • Have a small sample (biopsy) of the cells collected

    Sometimes the colposcopy shows abnormal cells, but it is not clear how serious the changes are. The doctor or nurse will collect a small sample (biopsy) of the cells. After the colposcopy, they send the sample to a laboratory to be checked under a more powerful microscope. This will show if you need treatment.

Making treatment decisions

Before any treatment, you should be given time and information to make a decision. If you have questions, want more time or are not sure, the treatment can always be done another day.

Your doctor or nurse will only offer treatment if they are sure the cells are very abnormal and there is a risk of cancer developing.

What is cervical intra-epithelial neoplasia (CIN)?

Cervical intra-epithelial neoplasia (CIN) is a term that describes the most common type of abnormal cells found during colposcopy.

CIN is graded by how deep the cell changes go into the surface of the cervix:

  • CIN 1

    CIN 1 means one third of the thickness of the cervical surface layer is affected by abnormal cells. This will often return to normal without any treatment at all. You will have further cervical smear tests or colposcopies to check the cells have improved. If these tests show the CIN 1 is not improving, you may be offered treatment.

  • CIN 2

    CIN 2 means two thirds of the thickness of the cervical surface layer are affected by abnormal cells. There is a higher risk the abnormal cells will develop into cancer.

    You may be offered treatment to stop this happening, or another colposcopy.

  • CIN 3

    CIN 3 means the full thickness of the cervical surface layer is affected by abnormal cells. CIN 3 is also called carcinoma-in-situ. This sounds like cancer, but CIN 3 is not cervical cancer. Cancer develops when the deeper layers of the cervix are affected by abnormal cells. You will be offered treatment to stop this happening.

We have more information about CIN.

Treating abnormal cells

After a colposcopy, you may be offered treatment to remove an area of abnormal cells. There are different types of treatment. You usually only need one treatment to remove the abnormal cells completely.

We have more information about treatment for abnormal cervical cells.

Follow-up after treatment

Treatments for abnormal cells of the cervix are usually very successful. You will be asked to have another cervical smear test about 6 months after your treatment. Your sample will be carefully checked for signs of abnormal cells and for high-risk HPV. What happens next depends on the results:

  • If the sample shows no HPV, you will be asked to have cervical screening again in 3 years. Your risk of developing more serious abnormal changes in this time is very low.
  • If the sample shows HPV, you will be asked to have another more detailed check-up, with a colposcopy.

Sometimes the colposcopy shows that an abnormal area of cells has come back, and more treatment is needed. This is not very common. The same types of treatment can often be used again to remove or destroy the abnormal area of cells.

Very occasionally, if the abnormal cells keep coming back after treatment, your doctor might suggest having surgery to remove the cervix completely. This usually means having an operation called a hysterectomy. Your doctor will explain if they think this is right for you.

After a hysterectomy, you may still need tests to check for abnormal cells. This is similar to having a cervical smear test, but the sample of cells is taken from the top of the vagina. It is sometimes called a vaginal vault smear.

If you are struggling to cope with worries about cervical screening, it may help to talk about it. You may want to talk to a friend or family member. Your GP or practice nurse can answer any questions you have and explain ways they can support you.

Macmillan is also here to support you. If you would like to talk, you can:

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Professor Nick Reed, Consultant Clinical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.