Cervical health and screening

What cervical screening is

Cervical screening looks for changes in the cells of the cervix that could develop into cancer if left untreated. The test does not diagnose cancer but identifies women who need further investigation or monitoring.

How the test works

A small sample of cells is taken from the cervix using a soft brush. The sample is sent to a laboratory and tested first for human papillomavirus (HPV), the virus that causes most cervical cancers. If HPV is detected the cells are examined for abnormal changes. The combination of HPV testing and cell examination is called HPV primary screening, the approach now used across the UK.

Who is invited

In the UK women and people with a cervix are invited for screening from age 25 to 64. Invitations come automatically through the NHS based on age and registered with a GP. Invitations are sent every 3 years for those aged 25 to 49, then every 5 years for those aged 50 to 64. People with weakened immune systems or following abnormal results may be screened more frequently.

What happens at the appointment

The appointment is typically with a practice nurse or GP and takes about 10 to 20 minutes. The actual test takes only a few minutes. The person undressing from the waist down lies on an examination couch. A speculum is inserted into the vagina to view the cervix. A soft brush takes a small sample of cells. Most women describe the procedure as briefly uncomfortable rather than painful.

After the test

Results are usually sent within 4 weeks. The letter explains the result and any next steps. Most results are normal and mean returning to routine screening at the next due date. Abnormal results trigger either repeat testing or referral to colposcopy (a more detailed examination of the cervix). Most abnormal results do not indicate cancer but identify changes that need monitoring or treatment.

The link explained

Almost all cervical cancers are caused by HPV. Understanding HPV helps make sense of why screening focuses on testing for the virus and why HPV vaccination is offered to young people.

What HPV is

Human papillomavirus is a group of more than 100 related viruses. Some types affect the genital area and are sexually transmitted. Most sexually active people will have HPV at some point in their lives. The immune system clears most HPV infections without intervention. A small proportion of infections persist and can cause changes in cells that may eventually lead to cancer.

High risk and low risk types

High risk HPV types (particularly types 16 and 18) are responsible for most cervical cancers. Low risk types can cause genital warts but rarely cause cancer. The current cervical screening programme tests for high risk HPV types specifically. Detection of high risk HPV does not mean cancer but indicates the person needs closer monitoring or further testing.

How HPV causes cancer

Persistent infection with high risk HPV can cause changes in cervical cells. Over years the changes can progress through stages of abnormality before potentially becoming cancer. The process typically takes 10 to 15 years from initial infection to cancer if changes go untreated. Screening identifies changes early when they can be treated effectively before becoming cancer.

HPV vaccination

The HPV vaccine is offered in schools to all children aged 12 to 13 in the UK. The vaccine protects against the HPV types responsible for most cervical cancers. The vaccine has been shown to significantly reduce cervical cancer rates in countries with established programmes. Vaccinated women still need cervical screening because the vaccine does not protect against all HPV types.

What screening results mean

Cervical screening results fall into several categories. Understanding each category helps put any abnormal result in context.

HPV negative result

No high risk HPV detected. This is the most common result. The next screening will be in 3 or 5 years depending on age. The risk of developing cervical cancer in the screening interval is very low. The cells are not examined further when HPV is not detected because the cellular changes that lead to cancer are essentially always linked to HPV.

HPV positive, normal cells

High risk HPV detected but the cells appear normal. The next screening will typically be in 12 months. Most HPV infections clear within 1 to 2 years. The follow up test checks whether the infection has cleared. Continued positive HPV with normal cells leads to closer monitoring. Most women with this result return to normal screening over time.

HPV positive, abnormal cells

High risk HPV detected and the cells show some abnormal changes. Referral to colposcopy is the standard next step. Colposcopy is a more detailed examination of the cervix using a special microscope. Sometimes a small tissue sample (biopsy) is taken for further testing. Most abnormal results do not indicate cancer but identify changes that can be monitored or treated.

When treatment is needed

If colposcopy and biopsy show significant cell changes, treatment may be recommended. The most common treatment is large loop excision of the transformation zone (LLETZ), a brief outpatient procedure that removes the abnormal area. The procedure is highly effective at preventing progression to cancer. Most women have no long term effects on fertility or pregnancy following treatment, though some increased risk of preterm birth has been reported.

Practical guidance

Attending cervical screening when invited is the most important step for cervical health. Other practical considerations also support cervical health and well being.

Attending screening

Cervical screening attendance has fallen in recent years and is now below target levels in many parts of the UK. Reasons include embarrassment, fear of pain, difficulty taking time off work and lack of awareness. Cervical cancer rates would fall significantly if screening attendance returned to higher levels. If you have concerns about attending speak to your GP practice about adjustments that might help.

When to seek advice

See your GP if you experience unusual vaginal bleeding (between periods, after sex or after menopause), unusual vaginal discharge, pain during sex or pelvic pain that does not settle. These symptoms can have many causes that are not cancer but should be assessed. Symptoms between screening intervals warrant prompt attention regardless of recent normal screening.

HPV transmission

HPV is sexually transmitted through skin to skin contact. Condoms reduce but do not eliminate transmission risk. Many people have HPV without knowing because it usually causes no symptoms. Having HPV is extremely common and does not indicate anything about an individual or their relationship. Reducing transmission risk involves the standard measures for sexually transmitted infections.

Living after treatment

Most women who have treatment for abnormal cervical changes have no long term effects. Returning to normal activity is usually possible within days to weeks depending on the procedure. Future fertility and pregnancy outcomes are generally unaffected. Continued attendance at screening is essential because abnormal changes can recur. Speak to your GP if you have specific concerns.

More on female health

For broader reproductive health our Vaginal Health: A Complete Guide covers related female anatomy. Pelvic Floor Health: What Every Woman Should Know covers another key area of female pelvic health. And How Female Health Changes From Puberty to Old Age covers the lifespan view.