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.
These pages should tell you everything you need to know about cervical screening. You can also watch a video that explains what you can expect to happen during cervical screening.
Testing for abnormal cells
Cervical screening isn't a test for cancer; it's 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 shows some abnormal changes in the cells of the cervix.
Most of these changes won't 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 they can't become cancerous.
About 3,000 cases of cervical cancer are diagnosed each year in the UK.
It's possible for women of all ages to develop cervical cancer, although the condition mainly affects sexually active women aged 30 to 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 who are registered with a GP are invited for cervical screening:
- aged 25 to 49 – every three years
- aged 50 to 64 – every five years
- over 65 – only women who haven't been screened since age 50 or those who have recently had abnormal tests
Being screened regularly means any abnormal changes in the cells of the cervix can be identified at an early stage and, if necessary, treated to stop cancer developing.
However, cervical screening isn't 100% accurate and doesn't prevent all cases of cervical cancer.
Screening is a personal choice and you have the right to choose not to attend.
What happens when you go for cervical screening?
Booking your test
You'll receive a letter through the post asking you to make an appointment for a cervical screening test. The letter should contain the details of the place you need to contact for the appointment.
Most women choose to go to their GP practice, although it may also be available at a well woman clinic or sexual health clinic. Screening is usually carried out by the practice nurse. You can ask to have a female doctor or nurse.
If possible, try to book an appointment during the middle of your menstrual cycle (usually 14 days from the start of your last period), as this can ensure a better sample of cells is taken.
If you use a spermicide, a barrier method of contraception or a lubricant jelly, you shouldn't use these for 24 hours before the test, as the chemicals they contain may affect the test.
Your screening appointment
The cervical screening test usually takes around five minutes to carry out. You'll be asked to undress from the waist down and lie on a couch, although you can usually remain fully dressed if you're wearing a loose skirt.
The doctor or nurse will gently put an instrument, called a speculum, into your vagina. This holds the walls of the vagina open so the cervix can be seen. A small soft brush will be used to gently collect some cells from the surface of your cervix.
Some women find the procedure a bit uncomfortable or embarrassing, but for most women it's not painful. If you find the test painful, tell the doctor or nurse, because they may be able to reduce your discomfort. Try to relax as much as possible, because being tense makes the test more difficult to carry out. Taking slow, deep breaths will help.
The cell sample is then sent off to a laboratory for analysis and you should receive the result within two weeks.
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 highest risk for cervical cancer.
After successful trials, HPV testing has been incorporated into the NHS Cervical Screening Programme.
If a sample taken during the 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, you'll carry on being routinely screened as normal.
If your sample shows more significant cell changes, you'll be referred for colposcopy without HPV testing.
In some areas, a test for HPV is the first test on the screening sample. In these cases, the sample is only checked for abnormal cells if HPV is found. If HPV isn’t found, you'll be offered a screening test again in three to five years (depending on your age).
Read about the results of cervical screening tests.