Anal warts are caused by the human papillomavirus (HPV), transmitted primarily through skin-to-skin contact during sexual activity. About 90% of cases are caused by HPV types 6 and 11, which are considered low-risk strains, meaning they cause warts but are not the types linked to cancer. You can get anal warts from any direct contact between infected skin and the skin around or inside the anus, and penetrative sex is not required.
How HPV Reaches the Anal Area
HPV spreads through direct contact with infected skin or mucous membranes. For anal warts specifically, the most common route is sexual contact involving the anal area. This includes anal intercourse, but also any skin-to-skin touching, fingering, or contact with shared sex toys. The virus enters through tiny breaks or micro-abrasions in the skin that you wouldn’t even notice.
One important detail: you don’t need to have anal sex to develop anal warts. The virus can spread from nearby genital skin to the perianal area during any kind of sexual contact. HPV on a partner’s genitals or hands can reach the skin around the anus without penetration ever occurring. Once the virus is present on the external skin, it can also spread inward along the anal canal over time.
Transmission Without Visible Symptoms
Most HPV infections are asymptomatic and transient. A person can carry and transmit the virus without ever developing visible warts themselves. This makes HPV extremely difficult to avoid through visual screening of a partner. Someone with no symptoms, no warts, and no idea they’re infected can still pass the virus through skin contact.
Not everyone who gets infected with HPV types 6 or 11 will develop warts. Many people clear the infection on their own without knowing they had it. But during that window, and potentially for some time after, they can transmit it to others.
The Incubation Period
After exposure, anal warts typically take 2 to 3 months to appear, though the incubation period can range from as short as 3 weeks to as long as 8 months. This long, variable window means you may not be able to trace exactly when or from whom you contracted the virus. It also means that warts can show up well after a sexual relationship has ended, which can create confusion about their origin.
Who Is at Higher Risk
Anyone sexually active can contract anal HPV, but certain factors increase the likelihood of developing visible warts. A weakened immune system is the most significant risk factor. People living with HIV, those taking immunosuppressive medications after an organ transplant, or anyone with a condition that reduces immune function are more likely to develop warts after HPV exposure and more likely to have larger or more persistent outbreaks.
Having multiple sexual partners increases cumulative exposure risk. Men who have sex with men face higher rates of anal HPV infection due to the frequency of direct anal contact, but anal warts occur across all genders and sexual orientations.
How Much Protection Condoms Provide
Condoms reduce the risk of HPV transmission but don’t eliminate it. A study published in The Journal of Infectious Diseases found that consistent condom use was associated with a 50% to 77% lower risk of HPV infection compared to inconsistent use. The reason condoms can’t fully prevent HPV is that the virus lives on skin surfaces that a condom doesn’t cover, including the base of the penis, the scrotum, the inner thighs, and the perianal skin. Any contact with these areas can transmit the virus.
Incorrect use further limits protection. Research has found that 43% of college-aged men reported putting on condoms after sexual contact had already started, which reduces their effectiveness. Still, consistent condom use meaningfully lowers your risk and remains worth practicing.
What Anal Warts Look and Feel Like
Anal warts appear as small, flesh-colored or grayish growths on or around the anus. They can be flat or raised, and sometimes have a rough, cauliflower-like texture. In early stages, they may be so small that you can’t see or feel them at all. Over time, they can grow in size or number, sometimes clustering together.
Many people with anal warts have no pain or discomfort. Others notice itching, occasional bleeding, or a feeling of a lump near the anus. Warts inside the anal canal are harder to detect on your own and are typically found during a clinical exam, where a provider uses a small scope to look inside.
Treatment and Recurrence
Anal warts are treatable but can be persistent. Treatment options generally fall into two categories: topical treatments that you apply at home over several weeks, and in-office procedures where a provider removes the warts through freezing, burning, or surgical excision. The right approach depends on the number, size, and location of the warts.
Recurrence is common because treatment removes the visible warts but doesn’t eliminate the underlying HPV infection from surrounding skin cells. Many people need more than one round of treatment. Over time, the immune system typically suppresses the virus enough to prevent new warts from forming, but this process can take months to years.
Prevention Through Vaccination
The HPV vaccine is the most effective way to prevent anal warts. It covers HPV types 6 and 11 (the strains behind 90% of wart cases) along with several cancer-causing strains. The vaccine is approved for people ages 9 through 45, and it works best when given before any HPV exposure, ideally in adolescence.
Among young men who have sex with men aged 16 to 20, vaccination was associated with a 76% reduction in the targeted HPV types found in the anal area. The vaccine does not treat existing infections or clear warts you already have, but it can protect against strains you haven’t yet encountered.