What Is HPV?

This informational guide, part of POPSUGAR's Condition Center, lays out the realities of this health concern: what it is, what it can look like, and strategies that medical experts say are proven to help. You should always consult your doctor regarding matters pertaining to your health and before starting any course of medical treatment.

Human papilloma virus is the most common sexually transmitted infection in the US. There are more than 100 types of HPV, and while most aren't dangerous, some can cause genital warts, and others may lead to cervical, vaginal, vulvar, head and neck, and anorectal cancers. "About 80 percent of sexually active people will have HPV at some point, and most will clear the infection on their own — but if it doesn't go away, it can cause serious health problems," notes Sangini Sheth, MD, associate professor of obstetrics, gynecology, and reproductive sciences at the Yale School of Public Health. (Although, while it's important to know that various cancer can be caused by HPV, the vast majority of people with HPV will not get cancer.) This guide lays out what the virus is, how it's transmitted, and how you can protect yourself from it.

There are 14 high-risk types of HPV, according to the National Cancer Institute. If you're infected with one of these types and your immune system doesn't fight it off within two years, the virus can turn normal cells in your body into precancerous cells. If those mutated cells aren't removed in time, they can become cancerous. "Both women and men can get HPV-related cancer," Dr. Sheth notes: HPV can affect cells in the cervix, vagina, vulva, penis, anus, or mouth and throat. The CDC reports that 25,719 cases of HPV-related cancers (most commonly cervical cancer) are diagnosed in women every year and 20,424 cases (most commonly oropharyngeal cancer, or cancers of the back of the throat) are diagnosed in men.

Genital warts, on the other hand, are from low-risk subtypes of HPV and will not turn into cancer. Many people are exposed to both subtypes since both can be asymptomatic and spread easily from skin-to-skin contact.

HPV infection occurs when the virus enters the body, often through a cut or abrasion on your skin. It spreads mostly through vaginal, oral, or anal sex — but as Dr. Sheth notes, "you don't have to have penetrative sexual activity to transmit it." Any intimate sexual contact can transmit HPV, and while condoms and dental dams can reduce the risk, since the virus lives on the skin in the areas outside of what the condoms/dental dams cover, they don't offer complete protection.

There are also certain risk factors for infection, according to the Mayo Clinic. These include:

There is no cure for HPV, but vaccination offers protection from nine of the high-risk strains of the virus, including the ones that are responsible for most types of HPV-related cancer. The vaccines can be given to children as young as 9 and are recommended starting at age 11 — but they can be given into adulthood. "While the vaccines are most effective in people who aren't yet sexually active or haven't had much sexual activity, they're approved for women and men up to age 45," Dr. Sheth notes. So if you haven't been vaccinated, talk to your doctor to see if it makes sense for you to get one. The vaccine doesn't treat or clear prior HPV infections, but it can protect you from strains you haven't yet been exposed to.

High-risk HPV does not present with warts, and many people carry the virus with no symptoms. If you do contract a subtype that causes genital warts, which look like soft, flesh-colored bumps on the genitals or anus and sometimes hurt or itch, doctors can typically medically or surgically remove them. "Treatment can get rid of the warts, but it doesn't necessarily get rid of the underlying HPV infection," Dr. Sheth notes. So ask your doctor about additional screenings you may need, and be aware that you could pass on HPV through future sexual contact. You don't have to abstain from sex just because you have HPV, but you should be aware of how to reduce your partners' risk, including when you should disclose your status to them.

Since HPV is so often asymptomatic, though, getting regular screenings is key. Pap tests, which look for cervical cancer, and HPV tests, which detect the strains of the virus that are known to lead to cervical cancer, are both useful tools. Your doctor can help you determine which type of test is right for you and how often you need them. For cervical-cancer screening, the American College of Obstetricians and Gynecologists recommends people age 21 through 29 get a Pap test every three years, unless a cervical abnormality is detected (in which case your doctor will recommend follow-up screenings); at age 30, your doctor may suggest getting a Pap and HPV test together every five years instead. (Currently, there's no approved HPV screening test for people with penises.)

Even so, you may have a normal Pap test with a negative HPV test and still have low levels of the virus. This means that your risk of cancer is very low, but you can still transmit the virus to others — hence the reason more than 80 percent of us are exposed at some point in our lives.