There are many types of HPV. Most resolve on their own and are unlikely to cause health problems. However, some types are high risk if the infection remains in the body.

Diagram showing where high-risk HPV can occur in the bodyShare on Pinterest
Illustration by Yaja Mulcare

Human papillomavirus (HPV) is the most common sexually transmitted virus, with doctors diagnosing roughly 13 million new cases every year.

The virus can pass on through skin-to-skin vaginal, anal, or oral sex. A person may not realize that they have the infection because it sometimes causes no symptoms.

Read on to learn about the types of HPV, as well as testing, treatments, and methods of prevention.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

Some types of HPV can cause cancer. This means that they are “high risk.”

When a high risk type of HPV infects cells, it changes how they communicate with one another. It also causes the cells to multiply. Usually, the immune system becomes aware of these cells and regulates them.

However, if these abnormal cells remain, they can continue to change and become precancerous.

HPV infects the thin, flat squamous cells that line the inner surface of some organs. For this reason, most HPV-related cancers are called squamous cell carcinomas.

The virus can also cause cancer in the glandular cells of the cervix, and this cancer is called adenocarcinoma.

There are more than 200 types of HPV. Doctors categorize them as oncogenic and non-oncogenic.

At least 14 types of HPV are oncogenic, meaning that they can cause cancer.

Non-oncogenic types usually cause no serious health issues. A doctor may refer to non-oncogenic types of HPV as “wart-causing HPV.”

Low risk

Low risk, or non-oncogenic, types of the virus rarely cause precancerous lesions, though they may still cause cellular changes.

If certain low risk types of HPV remain in the body, they can cause genital warts. These are benign growths that can develop around the genitals, groin, and anus.

Around 40 types of low risk HPV can infect the genital area. HPV types 6 and 11 are the most common causes of genital warts, together causing around 90% of cases.

Some low risk types can also cause the growth of warts in the mouth and throat. This condition is called recurrent respiratory papillomatosis, and it is more common in children than adults. “Papilloma” is another name for “wart.”

These growths are often benign, but they can cause severe airway obstruction and complications. In extremely rare cases, these warts become cancerous.

High risk

High risk HPV can cause several types of cancer if the immune system does not clear the infection.

Research suggests that HPV types 16 and 18 cause 70% of cervical cancer cases and precancerous cervical lesions. A small 2021 study demonstrated that just under half of the participants with HPV had type 16.

Estimates suggest that high risk HPV causes 3% of all cancer cases in females and 2% of all cancer cases in males in the United States.

Read more about HPV in males.

In the early stages, cervical cancer may not cause symptoms. If symptoms do occur, they commonly include:

  • abnormal vaginal bleeding
  • abnormal discharge from the vagina, with a strong odor or containing blood
  • pain during sex
  • pelvic pain

High risk HPV can also affect cells in other areas, and this may also develop into cancer. Other HPV-related cancers include:

The primary goal of cervical screening is to identify precancerous lesions caused by HPV. Doctors can remove lesions to prevent invasive cancers from developing.

Because HPV can develop without causing symptoms, regular screenings are an important way of detecting any changes early. Anyone with a weakened immune system or a medical history of cervical lesions may need more frequent screening.

Currently, cervical cancer is the only HPV-related cancer with a test that has been approved by the Food and Drug Administration.

The United States (U.S.) Preventive Services Task Force recommends that anyone who has a cervix and is 21–29 years old has cervical cancer screening every 3 years.

For anyone who has a cervix and is 30–65 years old, the task force recommends having an HPV test and Pap smear every 5 years or a Pap smear alone every 3 years.

The Centers for Disease Control and Prevention (CDC) do not recommend that males have routine testing for HPV.

Screenings

A Pap test, or Pap smear, was once the only type of screening for cervical cancer.

It involves collecting cells from the cervix. This only takes a few minutes and is an outpatient test. The doctor sends the sample to a lab, which checks for abnormalities in the cervical cells.

Cervical cancer screening now also includes HPV testing. In some cases, a doctor may recommend having a Pap test and an HPV test at the same time.

A Pap test involves checking the cells for precancerous changes. An HPV test looks for the DNA of the virus. A doctor may only order this test if a person likely has a high risk infection.

The results of both a Pap test and an HPV test give the doctor a clearer impression of a person’s cervical cancer risk. Negative results of both tests indicate a very low risk of developing precancerous cervical lesions over the next several years.

Learn what to expect from cervical screening.

There is currently no treatment for the infection. But treatments can address the health problems that HPV causes.

Although 20–30% of warts go away on their own over time, treatment can help manage outbreaks and reduce any discomfort. The treatment may involve applying a prescription cream or gel to the area or having the warts removed.

Surgery is necessary to remove precancerous cells caused by high risk HPV. This is to prevent the cells from becoming cancerous. A doctor can remove these cells from the cervix with a procedure called loop electrosurgical excision or with cervical cryotherapy.

The treatment for HPV-related cancer tends to be the same as the treatment for other cancers in the area. The best approach can depend on the location, type, and stage of cancer. Examples of these treatments include:

A person can reduce their risk of contracting HPV by:

  • getting the HPV vaccine
  • consistently using barrier methods, such as condoms or dental dams, during sex
  • limiting the number of sexual partners

Gardasil 9 is the HPV vaccine available in the U.S. It protects people from several high risk types of HPV, including types 16 and 18 — as well as the low risk types associated with warts.

The CDC says that, ideally, everyone should receive the HPV vaccine at ages 11–12 to reduce their risk of HPV-related cancer. This vaccination comes in two doses, 6–12 months apart. People aged 15–26 receive it in three doses.

After receiving the required vaccine doses, 98% of people develop the antibodies necessary to protect them from high risk strains, indicating that the vaccine is highly effective.

For people who are older than 27 and have a risk of new HPV infection, a doctor may discuss the benefits of receiving the vaccine, though it may be less effective.

For most people with HPV, the infection clears within 2 years.

With regular cervical screening, doctors are more likely to catch any cell abnormalities before they become cancerous.

If a doctor detects abnormal changes, treatment can start early, and this improves the outlook.

HPV infections are very common, and the body’s immune system usually clears them. The infection can remain in the body and cause health problems in some cases.

Getting the HPV vaccine and having regular cervical screening reduces the risk of these health problems.