HPV infections often go undetected because they don't cause warts or other lesions. Even if you don't exhibit signs and symptoms of the infection, they may emerge later and you may transmit the virus to someone else.

The signs and symptoms that do appear vary according to the type of HPV infection you may have:

• Genital warts. Genital warts are nonmalignant and appear as a flat lesion, a tiny cauliflower-like bump or a tiny stem-like protrusion. HPV infections of types 6 and 11 cause most genital warts. These HPV types are generally not associated with cancer.

  In women these warts appear most commonly on the vulva but may also occur near the anus, on the cervix or in the vagina. In men these may appear on the penis and scrotum or around the anus. Genital warts rarely cause discomfort or pain.

• Pre-malignant genital lesions. Certain HPV infections can cause cellular changes that result in precancerous lesions. These abnormalities are most often detected by a Pap test, a simple procedure to collect cells from the cervix or vagina for laboratory examination.

  Abnormalities that are determined to be "low grade" usually resolve — the cells return to normal — without treatment. HPV infections of types 6 and 11 are common causes of these low-grade abnormalities.

  High-grade abnormalities are less likely to resolve, and some will advance to cancer of the cervix, vagina or vulva. HPV infections of types 16 and 18 are the most common causes of high-grade abnormalities.

• Oral and upper respiratory lesions. Some HPV infections may cause warts and other lesions to form on your tongue, tonsils, soft palate, and larynx and in your nose. These lesions may be the result of low-risk HPV types, such as 6 and 11, or high-risk types, such as 16 and 18.

• Cervical cancer and other tumors. Most genital HPV infections of high-risk types don't develop into cancer; however, persistent infections — generally lasting more than two years — create a greater risk of cancer. Abnormal vaginal bleeding, such as excessively heavy menstrual bleeding or bleeding between periods, are common symptoms of cervical cancer.

  Virtually all cases of cervical cancer are caused by HPV infections. An estimated 11,000 women in the United States are diagnosed with cervical cancer annually, and more than 3,800 die of the disease each year. Worldwide, cervical cancer is far more common because many women lack access to Pap test screening. HPV types 16 and 18 account for about 70 percent of all cases of cervical cancer.

  HPV infections of type 16 and 18, as well as other high-risk types, may also contribute to cancers of the genitals, anus, mouth and upper respiratory tract.

• Common warts. Common warts are nonmalignant skin growths that usually appear on your hands, fingers or around fingernails. These warts appear as rough, raised bumps. They're generally nuisances because of their appearance, but they may also be painful or susceptible to injury or bleeding.

  Most children and adolescents have been exposed to HPVs that cause these warts, but only a small percentage actually get warts. Most people don't get common warts after age 20.

• Plantar warts. Plantar warts are hard, grainy, nonmalignant growths that usually appear on the heel or ball of your feet, areas that feel the most pressure. These warts may cause discomfort or pain. Although plantar warts are common in adulthood, most adults first encountered them during childhood or adolescence.
• Flat warts. Flat warts are flat-topped, slightly raised, nonmalignant lesions darker than your regular skin color. They usually appear on your face, neck, hands, wrists, elbows or knees. HPV infections that cause flat warts usually affect children, adolescents and young adults.

When to see a doctor
If you or your child has warts of any kind that cause embarrassment, discomfort or pain, seek advice from your doctor.

For women, it's important to have regular Pap tests. A Pap test is the best tool to detect an HPV infection that could lead to cervical cancer. The American College of Obstetricians and Gynecologists recommends that a woman begin annual Pap tests about three years after first having sexual relations or at age 21. Most women age 30 and older may have a Pap test every two to three years if tests are normal for at least three consecutive years.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

HPV infection occurs when the virus enters your body through a cut, abrasion or imperceptible tear in the outer layer of your skin. The virus is transferred primarily by skin-to-skin contact.

HPV infections associated with genital warts and related lesions are contracted through sexual intercourse, anal sex and other skin-to-skin contact in the genital regions. Some HPV infections that result in oral or upper respiratory lesions are contracted through oral sex.

Rarely a mother with an HPV infection may transmit the virus to her infant during delivery. This exposure may cause HPV infection in the baby's genitals or upper respiratory system.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

HPV infections are common. Risk factors for genital HPV infection include:

• Number of sexual partners. The greater your number of sexual partners, the more likely you are to contract a genital HPV infection. Having sex with a partner who has had multiple sex partners also increases your risk.
• Young age. Genital HPV infections are most commonly diagnosed with a Pap test in sexually active adolescent girls and women younger than 25 years of age. While this risk may be associated with increased sexual activity at this age, some research suggests that younger women may also be biologically more vulnerable to the virus. Adolescent boys and young men also are at increased risk, but the virus isn't often detected.
• Vulnerable immune systems. People who have vulnerable immune systems may be at greater risk of HPV infections. This vulnerability may be the result of HIV/AIDS or of immune-system suppressing drugs that enable people to receive an organ donation.

The primary risk factor for HPV infections that cause common warts, plantar warts and flat warts is young age. Children and adolescents are more likely to be vulnerable to these HPV infections than are adults. Other factors may include multiple exposures to HPVs, damaged or cut skin, and a vulnerable immune system.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

If you think you have an HPV infection, you'll probably first see your regular health care provider. If you have genital warts or lesions, you may be referred to a gynecologist, a doctor who specializes in women's health conditions.

Because appointments can be brief and because there's often a lot of ground to cover, it's a good idea to be well prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance.
• Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
• Make a list of all medications, as well as any vitamins or supplements, that you're taking.
• Write down questions to ask your doctor.

Some basic questions to ask your doctor include:

• What kinds of tests do I need?
• Should I be tested for other sexually transmitted diseases?
• Should my partner be tested or treated for HPV infection?
• Should I abstain from sexual activity during treatment? How long should I wait?
• How can I prevent HPV infection in the future?
• Is there a generic alternative to the medicine you're prescribing me?
• Are there any brochures or other printed material that I can take with me? What Web sites do you recommend?
• Under what circumstances should I plan for a follow-up visit?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.

What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:

• When did you first begin experiencing symptoms?
• What are your symptoms?
• Where have you noted lesions?
• Are the lesions painful?

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Diagnosing HPV infection may include the following tests:

• Visual inspection of any warts or lesions.
• Vinegar solution test. Your doctor may apply a vinegar solution that turns HPV-infected genital areas white. This may help in identifying difficult-to-see flat lesions. In most cases, there's no value in testing for the exact type of HPV infection that has caused visible warts or lesions because these HPV types don't cause cancer.
• Pap test. Your doctor collects a sample of cells from your cervix or vagina to send for laboratory analysis. If the Pap test results are inconclusive — the laboratory examination doesn't clearly indicate whether the cells have low-grade or high-grade abnormalities — your doctor may order a HPV DNA test. Your doctor won't order the HPV DNA test if the Pap test is clearly abnormal. In that case, the chance of the HPV DNA test being positive is so high, it doesn't yield useful information.
• DNA test. This test can detect the DNA of 13 high-risk HPVs, including types 16 and 18, from cell samples removed from the cervix. If the DNA test indicates a high-risk HPV infection, your cancer risk is greater. If your recent Pap tests have been normal and you're 30 years or older, your doctor may suggest an HPV DNA test as a supplement to your Pap test. If both tests are negative, your next combination Pap-DNA test would occur in three years. If the Pap test is negative but the DNA test is positive, your doctor will advise you on an earlier follow-up examination.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

There's no cure for HPV infection. In most cases, your immune system rids your body of the virus, and warts often go away without treatment.

A number of treatments — applied at home or performed by a doctor — are available to remove warts. These treatments appear to reduce the concentration of HPV, but they don't eliminate the virus. For example, even though you may have genital warts removed, you can still transmit HPV to a sexual partner.

Genital warts
Treatments for genital warts include:

• Imiquimod (Aldara), a prescription medication applied as a cream that may enhance your immune system's ability to fight HPV
• Podofilox (Condylox), also applied as a cream, which may destroy the genital wart tissue
• Trichloroacetic acid, a chemical treatment that burns off genital warts
• Freezing with liquid nitrogen (cryotherapy)
• Electrocautery, which uses an electrical current to burn off warts
• Surgical removal
• Laser surgery

Treatments for high-grade pre-malignant lesions
Your doctor will most likely not treat low-grade pre-malignant lesions, because they're likely to go away on their own and not develop into cancer. However, you'll need to return for follow-up Pap tests to make sure the problem has resolved.

Your doctor will most likely recommend removal of high-grade pre-malignant lesions, because they may develop into cancerous tumors. Treatments may include:

• Surgical removal
• Laser surgery
• Cryotherapy
• Electrocautery

Treatments for other warts
Treatments for common plantar and flat warts include:

• Salicylic acid, which removes layers of a wart a little bit at a time
• Imiquimod (Aldara)
• Cryotherapy
• Surgical removal
• Laser surgery

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.

Genital warts and related lesions
You can reduce your risk of developing genital warts and other HPV-related genital lesions by:

• Being in a mutually monogamous sexual relationship
• Reducing your number of sex partners
• Using a latex condom, which may prevent some but not all HPV transmission

A vaccine called Gardasil is available for women to prevent HPV infections of types 6, 11, 16 and 18. Ideally, a woman should receive this vaccine before becoming sexually active. The vaccine protects women only from contracting HPV infections of types they haven't already encountered.

According to the Centers for Disease Control and Prevention, the HPV vaccine should be a part of the regular immunization regime for 11- to 12-year-old girls. This vaccine is a powerful new tool in the fight against cervical cancer, and most pediatricians will strongly encourage HPV immunization for girls in the recommended age group.

Most adolescent girls or women who are sexually active will derive some benefit from HPV vaccination. If you've already acquired an HPV infection, it's unlikely that you've encountered all types included in the vaccine. For most people who are at risk of HPV infection, the potential benefits of getting the vaccine outweigh the known risks. Side effects in clinical trials were primarily mild pain at the injection site. Talk to your doctor about getting an HPV vaccination if you believe you're at risk of infection.

HPV vaccination is currently not recommended for boys or men, but the benefit of this immunization strategy is under investigation. Vaccination of males would likely have significant benefit for their future sexual partners.

Common warts
It's difficult to prevent HPV infections that cause common warts. If you have a common wart, you can prevent the spread of the infection and formation of new warts by not picking at a wart and not biting your nails.

Plantar warts
You may reduce the risk of contracting HPV infections that cause plantar warts by keeping your feet clean and dry, wearing clean socks, and wearing shoes or sandals in public pools and locker rooms.

©1998-2009 Mayo Foundation for Medical Education and Research (MFMER). Terms of use.