What cervical screening is

A cervical screening test is a free test to check the health of your cervix. The cervix is the opening to your womb from your vagina.

It's not a test for cancer, it's a test to see if you are at risk of developing cancer.

If you have a cervix, you can get cervical cancer. 9 in 10 cervical cancers are caused by certain types of human papillomavirus (HPV). HPV is spread through any kind of sexual contact with a man or a woman.

HPV that doesn't go away is called persistent HPV. This can cause changes to the cells of the cervix over time.

But HPV is not the only cause of cervical cancer. You can get cervical cancer if you have never had sex.

You should book your cervical screening test and go to it when it is due.

Who should have cervical screening

Reducing your risk

You can reduce your risk of getting cervical cancer by:

attending all your cervical screening appointments when they are due
getting symptoms checked
having treatment and extra tests when advised
getting the HPV vaccine in school or through the catch-up programme

How cervical screening helps prevent cancer developing

Cervical screening may check for:

human papillomavirus (HPV) - some types of HPV can lead to cell changes in your cervix and cancer
abnormal cell changes in your cervix - left untreated, these could turn into cancer

Your cervical screening test sample will be checked for HPV first.

If HPV is found, your same test sample will be checked to see if you have any abnormal (pre-cancerous) cells in your cervix. If abnormal cells are found, you will have a colposcopy.

If HPV is not found, we do not need to check for abnormal cells. This is because your risk of developing cervical cancer is very low if you do not have HPV.

This way of screening is called HPV cervical screening. If you have had a smear test in the past, having a cervical screening test will feel the same. You won't need to do anything different.

Screening benefits and limitations

What HPV is

HPV is the name for a very common group of viruses.

You can get it from any kind of physical or sexual contact of the genital area - even if you use a condom.

Sexual contact includes:

any skin-to-skin contact of the genital area
vaginal, oral or anal sex
sharing sex toys

There are over 200 different types of HPV. Most people will get some type of HPV during their lives.

For most people, the virus goes away on its own and does not cause any harm. Your body's immune system can clear it within 2 years.

HPV and cervical cancer

Some types of HPV are a high risk for causing cervical cancer.

Cervical screening looks to see if you have any of the most high-risk types of HPV.

Other types of HPV can cause genital warts. These are called low-risk types. Low-risk types do not cause cancer.

Almost all cervical cancers are caused by infection with high-risk types of HPV.

But most people who have HPV, even the types that cause changes to the cells of the cervix, do not develop cervical cancer.

Things that put you at risk of cervical cancer

HPV can be dormant (sleeping) in your body

There are usually no symptoms of HPV. You could have a HPV infection and not know it.

This makes it difficult to tell when you got the HPV infection.

For some people, HPV can stay dormant (sleeping inside the body) for years. It can then become active over time.

Dormant HPV will not be picked up on a screening test and will not cause you problems.

If it becomes active again, it will show up on your next screening test. It can only cause you harm if it stays positive for a long time (usually over 2 years).

That is why everyone with a positive HPV result has another test done 12 months later.

In most cases, it takes 10 to 15 years for persistent HPV to lead to abnormal cells and develop into cervical cancer.

This is why it is safe to wait up to 5 years between cervical screening tests.

HPV and your partner

Having HPV does not mean that your partner has recently had sex with someone else.

It may be difficult to know when you got HPV first. This is because HPV:

is very common in people who have had sex
can stay in your body for a long time without being active

HPV vaccine and screening

The HPV vaccine is given free to young people in their first year of secondary school. The vaccine catch-up programme is for some people age 16 or older who did not get the vaccine yet.

The HPV vaccine and regular screening later in life is an effective way to help prevent cervical cancer developing.

The HPV vaccine protects against 9 types of HPV which includes the types that are most likely to cause cancer.

But it does not protect you from all types of HPV. This is why your test might show you have HPV even if you have been vaccinated.

Warning

You are still at risk of developing cervical cancer if you have had the HPV vaccine. This is why screening is important.

It is best to get the vaccine before you become sexually active and exposed to types of HPV. But the vaccine can still give you protection if you are sexually active.

This is because you may not have been exposed to all the 9 types of HPV covered by the vaccine.

Screening limitations

Cervical screening tests are carried out on people who seem to be healthy. They do not have any symptoms of the condition they are being screened for.

But some people will still develop cervical cancer despite regular screening. While the risk of cervical cancer can be reduced, it cannot prevent all cases of cervical cancer.

Some abnormal cell changes may be missed and screening will not find every abnormal cell change.

You can get cancer at any time, including between your screening tests. We call cancer that is found in between screening tests, interval cancer.

Sometimes test results are inaccurate. We call these results false positives and false negatives.

HPV cervical screening was introduced in March 2020. This will mean fewer false negatives than before. This is because it is a better way to screen for cervical cancer.

Accuracy of screening results

Limitations of cervical screening