What is human papillomavirus (HPV)?

Human papillomavirus (HPV) is the most common sexually transmitted infection (STI) in men and women and the most easily transmitted. It is a viral infection that usually but not always causes skin or mucous membrane growths (warts) on your hands, feet, face, etc.

There are more than 100 types of human papillomaviruses (HPVs). Some types cause warts, and some can cause different types of cancer though not always.

About 30 HPV strains can affect your genitals, including your vulva, vagina, cervix, penis and scrotum, rectum, and anus.

Genital warts are caused by harmless forms of HPV and these forms that cause warts do not cause cancer.

The most common cancer caused by HPV is cervical cancer. Out of the 100 types of viruses, only about a dozen of them are associated with cervical cancer. It is the two varieties HPV 16 and HPV 18, which together account for 70 percent of all cervical cancers.

Other types of cancers that this virus can cause include cancers of the anus, penis, vagina, vulva, and back of the throat (oropharyngeal).

These infections are often transmitted through sexual acts or through other skin-to-skin contact.

In 9 out of 10 cases, HPV goes away on its own usually within two years without causing any health problems. But, when it does not go away, it can cause health problems like genital warts and cancer.

Early detection through regular Pap smears and prompt treatment can usually prevent this from happening.

Vaccines can help protect against the strains of HPV and can minimize your risk of getting genital warts or cervical cancer.

Presently, there is no way to screen for HPV, which makes it all the more imperative that parents get their children vaccinated.

All cervical cancers develop from untreated, high-grade lesions. Such lesions have a squamous cell abnormality, which contains precancerous cells.

Another serious but lesser-known danger of HPV is the high risk of developing head and neck cancer due to the spreading of the virus to the throat through oral sex. The rate of throat cancer is climbing very fast to the extent it is set to outpace cervical cancer. Experts are describing it as an epidemic.

A strong immune system, however, can fight the infection and it can put off the development of cervical cancer by about 10 to 15 years. In some cases, the immune system can even eliminate the infection.

How does HPV spread?

HPV spreads through vaginal, anal, and oral sex with someone who has the virus even though that someone does not have any signs or symptoms. Vaginal and anal sex are the most common ways to spread the virus.

It can also spread through close skin contact during sex. You can get it even if you have had sex with one person.

Your symptoms can develop years after having sex with an infected person. This makes it difficult to know when you first got it and from whom.

How common are HPV infections, warts, and cervical cancer?

The HPV infection is so common that almost every sexually active person will get the virus at some time in their life if they are not vaccinated. Six million Americans get infected each year. CDC estimates that there were 43 million HPV infections in 2018 with 13 million infections being new.

Genital warts, prior to the development of the HPV vaccines, affected about 340,000 to 360,000 people annually. At any given time, one in 100 sexually active adults in the U.S. has genital warts. These figures are of those people who got recorded and could be less than the actual number of people who get genital warts. Genital warts can go away on their own in a person with a strong immune system.

Cervical cancer: Every year, nearly 12,000 women living in the United States will have cervical cancer out of which more than 4,000 die from it even with screening and treatment.

Every year, about 19,400 women and 12,100 men suffer from other complications and cancers caused by HPV.


In most cases, the body’s immune system gets rid of the HPV infection before it can cause warts. When warts develop, they vary in appearance depending on which kind of HPV has caused it. Warts and cervical cancer are the two main manifestations of HPV.


  • Genital warts. Genital warts are flat. They can look like small cauliflower-like bumps or tiny stem-like protrusions. In women, they appear usually on the vulva but sometimes around the anus, on the cervix, or in the vagina. In men, the warts appear on the penis and scrotum or around the anus. They are usually painless but may itch or feel tender.
  • Common warts. Common warts usually appear on the hands and fingers as raised bumps.  They can be painful or may bleed due to injury.
  • Plantar warts. Plantar warts usually appear on the heels or balls of your feet. These warts are hard, grainy growths that might cause slight pain.
  • Flat warts. Flat warts are slightly raised lesions that are flat at the top. They can appear anywhere on the body. Children usually get them on the face, men tend to get them in the jaw area and women usually get them on the legs.

As explained above, genital warts may go away on their own basically due to a strong immune system. On the other hand, they may increase in size and multiply.

Cervical cancer

HPV infections are responsible for nearly all cervical cancers. However, it may take 20 years or longer for the cancer to develop after an HPV infection. Early cervical cancer typically doesn’t cause any symptoms.

Because it is without symptoms during the initial stages, it’s vital that women undergo regular screening tests to detect any precancerous changes in the cervix.

According to current guidelines,

  • Women of ages 21 to 29 years should undergo a Pap smear test every three years.
  • Women aged 30 to 65 years should continue to have a Pap test every three years. If they also get the HPV DNA test at the same time, they should do the test every five years.
  • Women over 65 years can stop testing if they’ve had three normal Pap tests in a row.


HPV infection, from skin-to-skin contact, occurs when the virus enters your body through a cut or small tear in your skin.

Genital HPV infections occur through sexual intercourse, anal sex, and skin-to-skin contact in the genital region. HPV infections in the mouth or throat occur through oral sex.

Pregnant mothers with genital warts can pass on the infection to their babies.

Being highly contagious, warts can spread through direct contact with a wart. Warts can also spread when you touch something that has come in contact with a wart such as public showers or swimming pools or a towel.

Risk factors

Risk factors for HPV infection include:

  • Having multiple sexual partners.
  • Age. Although they can affect people of any age, warts are most common among children and teenagers, peaking at 12 to 16 years.
  • Weakened immune systems.
  • Damaged skin. Punctured or opened skin is more prone to develop common warts.


There is no blood test to diagnose HPV. Your doctor might be able to diagnose HPV infection by looking at your warts.

If no genital warts are present, your doctor may order one or all of the following tests:

  • Vinegar (acetic acid) solution test. When vinegar solution is applied to the genital areas, HPV-infected lesions turn white. This helps in identifying lesions that are not easily visible.
  • Pap test. A sample of cells from your cervix or vagina is sent for laboratory analysis. Any precancerous cells can then be identified. If a person has receptive anal sex, the doctor may recommend an anal Pap smear.
  • DNA test. This test is done on cells from the cervix. It identifies the DNA of the high-risk varieties of HPV that cause genital cancers. It is especially recommended for women above 30 years along with the Pap test.
  • Biopsy. A biopsy of affected skin may reveal unusual cell changes.


HPV warts often recede without treatment, particularly in children. Since there’s no cure for the virus, the warts can come again either in the same place or elsewhere on the body.


Medications to remove the warts are applied directly to the warts. No oral medications or antibiotics are of any use in HPV treatment. Many applications may be necessary before they are completely removed.

Such medications include:

  • Salicylic acid. Salicylic acid works by removing the wart a little at a time. It is available over the counter and is mainly used for common warts. It can cause skin irritation and is not used for warts on the face.
  • Imiquimod. This cream is available as a prescription cream. It is used to treat genital and anal warts and works by increasing the activity of the body’s immune system. Common side effects include redness and swelling in the affected area.
  • Podofilox. This is another topical prescription, which works by destroying genital wart tissue. It may cause burning and itching.
  • Trichloroacetic acid. This acid chemically burns the warts on the palms, soles, and genitals.

Surgical and other procedures

If the above medications don’t work, your doctor might suggest removing warts by one of these methods:

  • Cryotherapy is freezing with liquid nitrogen.  Cryosurgery usually gets rid of most warts after 3 or 4 treatments. It removes genital warts but does not cure them.
  • Electrocautery is burning warts with a needle that has been heated with an electrical current.
  • Surgical removal involves scraping warts with a special instrument after first treating them with the salicylic acid solution.
  • Laser surgery. In this procedure, the wart is heated and destroyed using a laser beam. It may cause scarring.

Treatment for HPV in the cervix

Colposcopy is indicated if you have an abnormal HPV or Pap test. It is done using an instrument called a colposcope that provides a magnified view of the cervix. Your doctor will take samples (biopsy) of any areas of the cervix that look abnormal.

Any precancerous lesions are removed with any of the following options. They include

  • Cryosurgery
  • Laser
  • Surgical removal
  • Loop electrosurgical excision procedure (LEEP). LEEP uses a thin looped wire that is electrified to remove a thin layer of the suspicious section of the cervix
  • Cold knife conization is a surgical procedure that removes a piece of the cervix.

HPV vaccines

Children of age 11–12 years should get two doses of HPV vaccine, given at an interval of 6 to 12 months. The first dose can be given starting at age 9 years. Vaccines can be given to teens and young adults too. It is not given in pregnancy.

HPV vaccination is not recommended for everyone older than age 26 years. HPV vaccination of adults provides less benefit because most people in this age group are already exposed to HPV.

That HPV vaccination prevents HPV infections and HPV-induced cancer is proved by the fact HPV infections and cervical precancers have dropped since 2006, when HPV vaccines were first used in the United States.

  • Among teen girls, HPV infections have dropped 88 percent.
  • Among young adult women, infections with HPV have dropped 81 percent.
  • Among vaccinated women, the percentage of cervical precancers has dropped by 40 percent.

The HPV vaccines provide protection for a long time. Vaccinated people were followed up for about 12 years, and it was found that the protection by the vaccines against HPV was high with no signs of a decrease in its potency.