HPV (human papillomavirus): what it is, warts, screening and vaccine

HPV (human papillomavirus) is the most common sexually transmitted infection: almost everyone who has sex will get it at some point. No medicine removes the virus itself, but it usually clears on its own, and what it can cause (genital warts and cell changes that could lead to cancer) can be treated and largely prevented with vaccination and screening.

What HPV is

HPV is not one virus but a family of more than 200 types. Most cause no problems at all. They fall into two groups:

• Low-risk types can cause genital warts. They do not cause cancer.
• High-risk types, if the infection lasts for years, can cause cell changes that may turn into cancer if left unchecked. Mainly cervical cancer, but also cancer of the anus, throat, penis, vulva and vagina.

According to the World Health Organization (WHO), the immune system clears the infection in 90% of people, usually within one or two years. Even so, HPV causes almost all cervical cancers: around 660,000 new cases worldwide in 2022. Cancer usually takes 15 to 20 years to develop, which leaves plenty of time to find and treat changes early.

Symptoms

Most infections cause no symptoms at all. That is why most people never know they have had it.

• Low-risk types can cause genital warts: flat or raised skin growths, sometimes in clusters, on the genitals or around the anus. They are usually painless. They can appear weeks, months or even years after contact.
• High-risk types cause no symptoms while they change cells. Only screening picks them up.

How it is passed on

HPV spreads through skin-to-skin contact of the genital area during vaginal, anal or oral sex, or genital touching. Penetration and ejaculation are not needed. It can be passed on without any symptoms.

Because it can stay silent for years, there is no way to know when or from whom you got it. An HPV result does not mean your current partner has been unfaithful.

Genital HPV is not passed on by sharing cups, towels or toilets, or in swimming pools.

Tests and screening

There is no general test to tell whether you "have HPV". Men are not routinely tested, and there is no routine test for the mouth or throat. What does exist is cervical screening, which looks for high-risk HPV or cell changes before they cause problems. In Spain, for example, the national programme offers:

• Ages 25 to 29: a cytology (smear) test every 3 years.
• Ages 30 to 65: a high-risk HPV test. If negative, it is repeated after 5 years. If positive, a cytology test follows.

In England, the NHS invites people aged 25 to 64 every 5 years; the sample is tested for HPV first. Taking the sample is quick: a small brush collects cells from the cervix. It may feel a little uncomfortable but should not hurt; if it does, say so. Genital warts are diagnosed with a simple examination. For other STIs, see how often to have an STI test.

Treatment

There is no treatment for the virus itself, and usually none is needed. What is treated are its effects:

• Genital warts can be treated with prescription creams or removed in clinic, for example by freezing. They can come back. It is best to avoid sex until they have gone.
• Cervical cell changes found by screening are monitored or removed with a simple procedure, with very good results.

Having HPV does not mean you have to stop having sex. Condoms lower the risk of passing it on.

HPV and pregnancy

HPV does not usually affect pregnancy or the baby. Warts may grow a little during pregnancy. If you are due for screening, it can be done while pregnant. The vaccine is not given during pregnancy. Find out more in our pregnancy and postpartum guide.

Prevention: vaccine, screening and condoms

• Vaccine: it is safe and highly effective against the types behind most HPV cancers and warts. It works best before someone becomes sexually active. WHO recommends it from age 9. In the UK, girls and boys are offered it at school at around 12 to 13, and those who missed it can catch up. If you are an adult, ask your GP whether it is right for you.
• Screening: even if you are vaccinated, keep going to cervical screening.
• Condoms lower the risk but do not fully protect, because HPV can be on skin they do not cover. Check the most common condom mistakes.

When to get help

Book an appointment if you notice lumps or warts on your genitals or anus, if you are due for screening or have received an invitation, or if you bleed after sex or between periods. Ask too if you would like the vaccine or have questions about a result. A positive HPV result is not a cancer diagnosis: it means you need follow-up.