What is cervical screening?

The NHS cervical screening programme uses tests to:

  • check for abnormal changes in the cells of the cervix
  • decide if these changes should be treated.

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 they can develop into cancer of the cervix (cervical cancer).

Abnormal changes cause no symptoms. So you will not know if you are affected unless you have cervical screening. Screening finds any abnormal cell changes. It then identifies the changes 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?

The NHS offers regular cervical screening from the age of 25 to 64 to women who are registered with a GP.

Cervical screening is important for anyone in this age group who:

  • has a cervix
  • and has ever been sexually active with a man or a woman.

If you are a trans man and still have a cervix, you should have screening too. However, you may not be sent an invitation if you are registered as male with your GP. Let your GP know if you want to have cervical screening, so they can arrange regular tests for you.

If you are pregnant, you can usually delay having your screening test. Your GP or midwife will explain if there is a reason you need the test while you are pregnant. It is safe to have the test but it may cause a small amount of bleeding afterwards. This is normal and does not affect your baby.

You do not need screening if:

  • you are a trans woman
  • 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 screening for any reason, ask your GP for advice.

HPV and cervical screening

Abnormal cell changes on the cervix are usually caused by a common infection called the human papilloma virus (HPV). There are different types of HPV. The types that cause abnormal cervical cell changes are called high-risk HPV. These types can pass from person to person during sex.

HPV is very common and most people are affected by it at some point. Usually the body’s immune system gets rid of it 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 clear the infection and the virus stays in the body for longer. If the cervix is affected by HPV, it means the virus may cause damage that over a long time can develop into abnormal cells.

If your cervical screening test shows HPV or abnormal changes, this does not reveal details about your sex life. The virus can be passed on through any type of sexual contact. Using a condom or other barrier contraception may reduce the risk of infection with HPV but does not offer complete protection.

HPV can affect people who:

  • have had one or more sexual partners
  • have had sex with men or with women
  • are in a long-term relationship with one person.

If you are in a sexual relationship, it is likely that your partner has already been affected by HPV. This is unlikely to cause them any harm. They do not need to be tested or treated for it.

Some people feel ashamed of having a condition that is linked to sex or worry what others will think. If you have worries or questions about HPV, ask your GP or nurse.

Cervical screening results

Your cervical screening test may show:

  • Normal cells – Your sample showed no changes to the cells in the cervix. This is also called a negative result. You will be asked to come for your regular screening again in three years (or five years if you are over 50).
  • The result was unclear – This may mean there were not enough cells in the sample. Or if you had your period or an infection, these may have affected the result. You will be asked to have the test again.
  • Abnormal cells – Your sample showed some type of change to the cells. Depending on the type of change you might need further tests to find out if these need treatment.

Abnormal cells

If your cervical screening test shows abnormal cells, this does not mean you have cancer. But it can still be a shock if you are told you need more tests. You should have the chance to talk about your results with your GP or practice nurse. You can also call our cancer support specialists for free on 0808 808 00 00. We also have information about waiting for test results.

People often feel anxious waiting for the next appointment and more test results. This can be the hardest part of having cervical screening.

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.

 

Slightly abnormal or mild changes

Most abnormal results from the cervical screening test show only very minor or slight changes. This is also called borderline changes (low-grade dyskaryosis).

Slightly abnormal changes often go back to normal over time. If you get a slightly abnormal result, what happens next depends on where you live.

  • If you live in England, Wales or Northern Ireland

    Your sample of cells will be tested for the human papilloma virus (HPV). If your sample does not show HPV, the changes are likely to go back to normal on their own. You will be asked to come for your regular screening again in 3 years (or 5 years if you are over 50). 

    If your sample shows HPV, there is a chance the cells will not improve. Your GP will arrange for you to have a test called a colposcopy to look at the cervix in more detail.

  • If you live in Scotland

    You may be asked to have another cervical screening test in a few months to check the cells have gone back to normal. Or your GP may arrange for you to have a test called a colposcopy to look at the cervix in more detail.

    From 2019 or 2020, your sample of cells will be tested for the human papilloma virus (HPV) instead. 

If you smoke, slightly abnormal or mild changes are less likely to go back to normal. If you want to give up smoking, your GP can give you advice. We also have more information about giving up smoking.

Very abnormal (moderate or severe) changes

Sometimes the cervical screening test finds very abnormal cell changes. This is also called high-grade dyskaryosis. If you have this type of change, your GP will arrange for you to have a test called a colposcopy to look at the cervix in more detail.

Other abnormal results

Sometimes the screening test finds other types of changes.

  • Glandular intra-epithelial neoplasia (CGIN)
    Changes in a type of cell that lines the cervical canal can be a sign of a condition called cervical glandular intra-epithelial neoplasia (CGIN). If left untreated, CGIN may develop into a less common type of cervical cancer called adenocarcinoma. If you have signs of CGIN, your GP may arrange for you to have a test called a colposcopy to look at the cervix in more detail. Or they will arrange for you to be seen by a gynaecologist. This is a doctor who treats female reproductive system problems.
  • Cervical cancer
    Rarely, cervical screening finds changes that may be a sign of very early cervical cancer. You will have a colposcopy to look at the cervix more closely. If any cancer is found you will see a gynaecologist for advice about treatment.

We have more information about treating cervical cancer.

Colposcopy

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

The colposcopy shows abnormal areas of the cervix and how abnormal the cells there are. Sometimes the doctor or nurse can see during the test that the cells are very abnormal but it is not clear how serious the changes are.

They may:

If you have a biopsy, results may take 2 or 3 weeks. Ask your doctor or nurse when you will get the results.

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 – one-third of the thickness of the surface layer is affected.
  • CIN 2 – two-thirds of the thickness of the surface layer is affected.
  • CIN 3 – the full thickness of the surface layer is affected.

CIN 3 is also known as carcinoma-in-situ. Although this sounds like cancer, CIN 3 is not cervical cancer. Cancer develops when the deeper layers of the cervix are affected by abnormal cells.

Cells showing CIN 1 will often return to normal without any treatment at all. You will have further screening 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 and 3 have a higher risk of developing into cervical cancer. You will usually be offered treatment to prevent 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. To check, you will be asked to have another cervical screening test about 6 months after your treatment. Your sample will be carefully checked for signs of abnormal cells and for the human papilloma virus (HPV).

If your sample shows no HPV and normal cells, or only slightly abnormal changes, you will be asked to come for cervical screening again in 3 years. Your risk of developing more serious abnormal changes in this time is very low.

If your sample shows HPV or more abnormal changes, you will be asked to come for a more detailed check up with a colposcopy again. For some people, the colposcopy will show that an abnormal area of cells has come back and more treatment is needed. This is not very common but it can happen. The same types of treatments 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 it is right for you.

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

We have more information about having a hysterectomy as a treatment for cancer.

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