Why have one?

A smear test can pick up abnormal changes in cervical cells, which are usually easy to treat if they are caught at an early stage, but it is not a test for cancer itself. It can also find signs of some hidden infections such as Human Papilloma Virus (HPV), which is a form of wart virus that's been linked to cancer of the cervix.

Who should have them?

Your GP (doctor) will send you a letter when you're 25 asking you to book an appointment for a smear test. If the smear shows nothing abnormal, the test is repeated at three year intervals until you are 49, and at five year intervals until you are 64.  Note that you cannot be screened during your period. The best time to have the test is roughly two weeks after the first day of your period.

Dr Rupal Shah explains what the HPV vaccine is and the reasons for getting immunised.

A woman's chance of developing cervical cancer is significantly reduced if she's never had any sexual partners. There's still a small chance, so it's worth getting tested regardless, but if you haven't been sexually active you can choose to decline the smear test appointment if you want to. If you've been sexually active in the past and have recently had a 'dry spell', it's recommended that you get tested as normal.

Why aren't women under 25 offered one?

In the light of medical evidence published in 2003, women under 25 are not offered a smear test because abnormalities in their cervixes are rarely linked to cervical cancer. Changes in the young cervix are normal and unnecessary treatment could have consequences for a woman's fertility.

What are they like?

The test is very simple and quick. The woman lies on her back with her knees apart and her heels up towards her bottom. The doctor or nurse inserts a sterile instrument called a speculum into the vagina to make the cervix easier to see. A tiny spatula is then used to gently scrape some cells from the cervix. Sometimes a very small brush can be used too. The whole process should be painless, but can sometimes be a bit uncomfortable, especially if you're nervous.

A quick pelvic examination is sometimes carried out afterwards at some clinics, with the doctor or nurse using a gloved hand to check the vagina, womb, and ovaries. You may also be offered a blood pressure test and breast examination. Some women find they bleed slightly after a smear, so it's a good idea to have a small sanitary towel or panty liner in your bag, just in case.

Vaccine against cervical cancer

A vaccine has been introduced to protect against HPV, which can increase the risk of developing cervical cancer. HPV is a virus that is passed on by sexual activity and there are more than 100 different types, including genital warts.

The vaccination programme started in September 2008, and all girls born on or after September 1 1990 will be offered the vaccine by the end of the academic year 2009/10.

The vaccine will protect against the two strains of the HPV virus that cause 70% of cases of cervical cancer, the second most common cancer in women worldwide. There are two different types of vaccine, Cervarix and Gardasil

Updated: 25/03/2011