Human papillomavirus (HPV) refers to a group of viruses.

More than 100 types of HPV exist, and at least 40 of them are spread through sexual contact. There are both low- and high-risk types.

Although HPV typically doesn’t cause any symptoms, some types can cause genital warts. Some types can also lead to certain cancers if left untreated.

Read on to learn about the vaccine and other ways to reduce your risk, how to get a diagnosis, what to expect from treatment, and more.

HPV is the most common sexually transmitted infection (STI).

According to the Centers for Disease Control and Prevention (CDC), approximately 79 million Americans have an active HPV infection. As many as 14 million Americans are newly infected each year.

Most people who are sexually active — regardless of anatomy or gender — will contract at least one form of HPV in their lifetime.

HPV is a virus, like the common cold or flu, that has many different variations.

Some forms of HPV can cause papillomas (warts), which is how the virus got its name.

HPV is primarily transmitted through skin-to-skin contact. In most cases, this refers to genital touching or intercourse.

This includes:

  • vulva to vulva
  • vulva to penis
  • vagina to penis
  • penis to penis
  • penis to anus
  • fingers to vagina
  • fingers to penis
  • fingers to anus

HPV can also be spread though oral sex. This includes:

  • mouth to vulva
  • mouth to vagina
  • mouth to penis
  • mouth to testicles
  • mouth to perineum (between the genitals and anus)
  • mouth to anus

Generally speaking, any genital or anal contact can transmit HPV, even if no symptoms are present.

In rare cases, HPV can be transmitted from the parent to the baby during vaginal delivery.

Overall, it’s unlikely that genital HPV — with or without warts — will cause complications during pregnancy or delivery.

HPV affects everyone. However, there are certain situations that only affect individuals who have a penis.

For example, those who act as the receiving partner in penile-anal sex are more likely to develop HPV than those who have penile-vaginal sex only.

Although HPV-related cancers are less common among individuals who have a penis, some people may be more susceptible — such as those with HIV or other causes of a weakened immune system.

Individuals who have a penis and are affected by both HPV and HIV may develop genital warts that are more severe and more difficult to treat.

You probably won’t know for sure unless you ask a doctor or other healthcare provider to screen for it.

They can take a sample of the cells inside your cervix to test for the presence of HPV.

You may be able to self-diagnose if you develop warts, but you should see a doctor to confirm the underlying cause.

HPV usually occurs without symptoms. Because of this, most people don’t know that they carry the virus.

In most people, the virus will actually clear up spontaneously, so they may never know they had it.

When symptoms do occur, they usually appear in the form of genital warts. You may notice a single bump or a group of bumps.

These bumps may be:

  • itchy
  • the color of your skin or white
  • raised or flat
  • cauliflower-shaped
  • about the size of a pin head (1 millimeter) to about the size of a cheerio (1 centimeter)

Not all genital bumps are warts, so it’s important to see a doctor or other healthcare provider for diagnosis.

They can determine the underlying cause and advise you on any next steps.

If you have warts or other genital sores, your provider may use a scalpel to take a small skin cell sample (biopsy) from the affected area.

If you aren’t experiencing symptoms, the diagnostic process typically begins with an abnormal result on your pap test.

When this happens, your provider may order a second pap test to confirm the original results or move straight to a cervical HPV test.

Your provider will collect another cervical cell sample, only this time they’ll have the lab technician test for the presence of HPV.

If they detect a type that may be cancerous, your provider may perform a colposcopy to look for lesions and other abnormalities on the cervix.

Your provider is unlikely to perform an anal pap smear unless you develop anal warts or other unusual symptoms.

There isn’t a specific test available to test for oral HPV, but your provider can perform a biopsy on any lesions that appear in the mouth or throat to determine if they’re cancerous.

A pap test doesn’t test for HPV. It can only detect the presence of abnormal cells.

In many cases, an abnormal result stems from:

  • a poor tissue sample
  • current spotting or menstruation
  • recent use of feminine hygiene products
  • recent penile-vaginal sex

An abnormal result can also be a sign of other STIs, include genital herpes and trichomoniasis.

An HPV test, on the other hand, can detect the presence of HPV. It can also identify which strains are present.

No, typically, the HPV test isn’t currently included in standard STI screening.

If you’re under the age of 30, your provider typically won’t recommend a HPV test unless you have an unusual pap test result.

If you’re between the age of 30 and 65, doctors usually recommend:

  • a pap test every 3 years
  • a HPV test every 5 years
  • a pap and HPV test together every 5 years

HPV doesn’t have a cure, but many types will go away on their own.

According to the CDC, more than 90 percent of new HPV infections clear or become undetectable within 2 years of infection.

In many cases, the virus clears or becomes undetectable within 6 months.

If the virus doesn’t clear, your provider will work with you to treat any cervical cell changes or HPV-related warts.

If you have genital warts, chances are they’ll go away on their own.

If they don’t, your provider may recommend one or more of the following:

  • imiquimod (Aldara), a topical cream that will boost your immune system’s ability to fight off the infection
  • sinecatechins (Veregen), a topical cream that treats genital and anal warts
  • podophyllin and podofilox (Condylox), a topical plant-based resin that destroys genital wart tissue
  • trichloroacetic acid (TCA), a chemical treatment that burns off internal and external genital warts

Your provider may recommend surgery to remove warts that are larger or unresponsive to medication. This can include:

If HPV has caused cancer in the body, your provider will recommend treatment dependent on how much the cancer has spread.

For example, if the cancer is in its earliest stages, they may be able to remove the cancerous lesion.

They may also recommend chemotherapy or radiation to kill the cancerous cells.

In some cases, genital warts that are left untreated will go away on their own. In others, the warts may stay the same or grow in size or number.

If your provider detects abnormal cells, you should follow their recommendations for additional testing or treatment to remove the cells.

Changes that are left unmonitored or untreated may become cancerous.

Having HPV won’t affect your ability to conceive. However, certain treatments for HPV might.

This includes:

These procedures are used to remove abnormal tissue. Cell removal can change your cervical mucus production or cause the cervical opening to narrow (stenosis).

These changes may make it more difficult for sperm to fertilize an egg.

If you’re already pregnant, HPV shouldn’t affect your pregnancy. Passing the virus or genital warts is unlikely during pregnancy or delivery.

In rare cases, if genital warts are large or widely spread, they may block the vaginal canal or otherwise complicate vaginal delivery.

If this happens, your doctor will likely recommend a cesarean delivery.

Having HPV doesn’t mean you’ll develop cancer. Oftentimes, the infection will clear without ever causing genital warts or other complications.

If your provider detects abnormal cells, they can perform an HPV test to determine whether you have HPV and, if you do, whether it’s a “high-risk” strain.

If left untreated, high-risk strains can lead to the following cancers:

  • oral
  • cervical
  • vaginal
  • vulvar
  • anal

Yes, and this can happen in a number of ways. For example:

  • you may have multiple strains of HPV at once
  • you may clear one type of HPV and develop the same type later on
  • you may clear one type of HPV and develop a different type later on

It’s important to note that clearing the virus once without treatment doesn’t mean that you’ll be able to do so a second time.

Your body may respond to the same strain differently at different times in your life.

You can reduce your risk for HPV if you:

  • Get the HPV vaccine. The HPV vaccine helps prevent strains known to cause warts or become cancerous.
  • Use a condom each time you have sex. Condoms don’t provide complete protection against HPV and other STIs, but correct use during oral, vaginal, and anal sex can dramatically decrease your risk.
  • Limit your number of sex partners. This recommendation is a law of probabilities — the more partners you have, the more people are likely to expose you to HPV.
  • Don’t douche. Douching removes bacteria from the vagina that can help keep HPV and other STIs at bay.

The HPV vaccine helps prevent strains known to cause genital, anal, or oral warts, as well as certain cancers.

The U.S. Food and Drug Administration (FDA) approved three HPV vaccines:

  • Cervarix
  • Gardasil
  • Gardasil 9

While all three have been approved by the FDA, only Gardasil 9 (9vHPV) is distributed in the United States as of 2016.

The vaccine involves a series of two or three shots administered over the course of six months.

You must receive the full course of medication in order to fully benefit from the vaccine.

Most doctors recommend getting the HPV vaccine around age 11 or 12, or before becoming sexually active. However, you may still receive some benefit even after becoming sexually active.

The FDA has approved the HPV vaccine for adults up to age 45.

If you’re older than age 45 and wondering if you may benefit from the HPV vaccine, talk to a doctor or other healthcare provider.

The vaccine only protects against HPV strains associated with warts and cancer.

Each of the three vaccine types provides different levels of protection:

  • Cervarix protects against HPV types 16 and 18.
  • Gardisil protects against HPV types 6, 11, 16, and 18.
  • Gardisil 9 protects against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58.

HPV types 16 and 18 are responsible for approximately 70 percent of all cervical cancers.

HPV types 31, 33, 45, 52, and 58 are responsible for 20 percent of all cervical cancers.

HPV types 6 and 11 aren’t cancerous, but they can cause genital, anal, or oral warts.

As Gardasil 9 gives the most protection from all the high-risk HPV types, this is now the only recommended vaccine given in the United States.

The vaccine plays an important role in preventing HPV, but it doesn’t protect against every possible strain. Using a condom with oral, vaginal, and anal sex can provide additional protection.

If you have a primary care doctor or gynecologist, talk to them about the vaccine. The vaccine is also available at most health departments and health clinics.

The vaccine costs about $178 per dose, so it may cost as much as $534 to receive the full course of medication.

If you have health insurance, the vaccine is fully covered as preventive care until age 26.

If you’re over the age of 26 or without insurance, ask your provider if they have any patient assistance programs available.

You may be able to get the vaccine at no or a reduced cost.

Although HPV is usually harmless, certain strains can cause warts or become cancerous.

According to the CDC, the vaccine can prevent most HPV-related cancers from ever occurring.

If you have questions about HPV or getting vaccinated, talk to a healthcare provider.

They can discuss your individual risk for developing HPV, as well as confirm whether you were vaccinated earlier in life or if you could benefit from it now.