A cervical screening test (previously known as a smear test) is a method of detecting abnormal cells on the cervix. The cervix is the entrance to the womb from the vagina.
Detecting and removing abnormal cervical cells can prevent cervical cancer.
Cervical screening is not a test for cancer; it is a test to check the health of the cells of the cervix. Most women's test results show that everything is normal, but for around 1 in 20 women the test will show some abnormal changes in the cells of the cervix.
Most of these changes will not lead to cervical cancer and the cells may go back to normal on their own. However, in some cases, the abnormal cells need to be removed so that they cannot become cancerous.
About 3,000 cases of cervical cancer are diagnosed each year in the UK, which amounts to 2% of all cancers diagnosed in women.
It's possible for women of all ages to develop cervical cancer, although the condition mainly affects sexually active women between the ages of 30 and 45. The condition is very rare in women under 25.
The cervical screening programme
The aim of the NHS Cervical Screening Programme is to reduce the number of women who develop cervical cancer and the number of women who die from the condition. Since the screening programme was introduced in the 1980s, the number of cervical cancer cases has decreased by about 7% each year.
All women aged between 25 and 64 are invited for cervical screening. Women aged between 25 and 49 are invited for testing every three years, and women aged between 50 and 64 are invited every five years.
Being screened regularly means that any abnormal changes in the cells of the cervix can be identified at an early stage and, if necessary, treated to stop cancer developing.
It is estimated that early detection and treatment can prevent up to 75% of cervical cancers.
Read about why cervical screening is recommended and when cervical screening is recommended.
The cervical screening test
The cervical screening test usually takes around five minutes to carry out. An instrument called a speculum will be gently inserted into your vagina to hold the walls of your vagina open so that your cervix is visible. A small soft brush will be used to take some cells from the surface of your cervix.
The sample of cervical cells will then be sent to a laboratory and examined under a microscope to see whether there are any abnormal cells.
Some women may find the procedure a bit uncomfortable or embarrassing, but for most women it is not painful.
If the test picks up abnormalities in the cells in your cervix, it may be recommended that you have treatment to remove them, or further tests in a few months to see if they return to normal on their own.
Read about what happens during cervical screening and treating abnormal cells in the cervix.
Human papilloma virus testing
Changes in the cells of the cervix are often caused by the human papilloma virus (HPV). There are more than 100 different types of HPV. Some types are high risk and some types are low risk. HPV-16 and HPV-18 are considered to be high risk for cervical cancer.
After successful trials, HPV testing has been incorporated into the NHS Cervical Screening Programme.
If a sample taken during for cervical screening test shows low-grade or borderline cell abnormalities, the sample should automatically be tested for HPV. If HPV is found in your sample, you should be referred for a colposcopy for further investigation and, if necessary, treatment. If no HPV is found, then you will carry on being routinely screened as normal.
If your sample shows more significant cell changes you will be referred for colposcopy without HPV testing.
In some areas, a test for HPV will be carried out as the first test on the screening sample. In these cases, the sample will only be checked for abnormal cells if HPV is found. If HPV isn’t found, you will be offered a screening test again in three to five years time (depending on your age).
Read about the results of cervical screening tests.