What is HPV?

If you haven't heard of HPV, you're in good company - but you almost certainly will encounter it at some point. It's the most common sexually transmitted infection in the world, and most people who get it never know. This article walks through what HPV actually is, why most cases are nothing to worry about, and the small share that matter.

What is HPV?

HPV stands for Human Papillomavirus. It's not one virus but a family of more than 200 related viruses. Some cause harmless warts on hands or feet. Some cause genital warts. A small group can cause cancer, including cervical cancer, if they don't clear from your body over many years.

HPV spreads through intimate skin-to-skin contact. The CDC notes you can catch it:

How common is it?

Most sexually active people get HPV at some point. It's that common.

In the United States, the CDC estimates over 42 million people currently carry a disease-causing type of HPV, with around 13 million new infections every year. The numbers are similar everywhere HPV is studied. Whatever your age, sexual history, or relationship status, getting HPV doesn't reflect anything about you - it reflects how widespread the virus is.

Most infections clear on their own

Here's the news that should change how you read everything that follows: most HPV infections clear on their own.

The World Health Organization puts it directly:

The CDC adds:

You usually don't know you have HPV. There are no symptoms in most cases. Your immune system handles it the way it handles thousands of other things every day, and you go on with your life.

Which HPV types matter?

HPV types fall into two groups:

• Low-risk types (like HPV 6 and 11) cause genital warts. They don't cause cancer.
• High-risk types (like HPV 16 and 18) can cause cervical cancer if they persist for many years.

Two types do most of the damage. The WHO reports that the licensed HPV vaccines all protect against types 16 and 18 specifically because they:

That's why you'll see these two numbers - 16 and 18 - turn up so often in cervical health information.

What if it doesn't clear?

For a small share of people, the immune system doesn't clear a high-risk HPV infection. Persistent infection can, over time, cause changes in cervical cells that may eventually become cancer.

The 'over time' part is critical. The WHO writes:

A 15-to-20-year window is what makes cervical screening so effective. There is plenty of time to detect changes and treat them long before they become dangerous.

This is the entire reason the screening program exists: to catch cell changes during that long, silent window, when they're easy to manage.

What you can do

Two things have strong evidence for protecting against cervical cancer:

• HPV vaccination covers the most dangerous types. Read more about the HPV vaccine
• Cervical screening finds changes early, when treatment is simple. Read more about cervical screening

Both are core to the WHO's global strategy to eliminate cervical cancer. If you've done one, you've done meaningful work; if you've done both, you've done what the evidence currently supports.

Bottom line

HPV is common, usually clears on its own, and rarely causes cancer - but the small share that does is exactly why we vaccinate and screen. Now you know what HPV actually is. The next time you read about it, you have context.