Around 10% of people who catch HPV will go on to have a long-lasting infection that increases the risk of cancer. From there, it can take up to 20 years for cancer to emerge.

Over 200 types of human papillomavirus (HPV) exist. Some are high risk types that can turn into cancer if the body fails to get rid of the infection. In total, 12 HPV types are considered to be high risk.

Most of the time, HPV doesn’t develop into cancer. 70% of infections clear up on their own within a year, with 90% clearing up within 2 years.

HPV 16 and 18 are behind the vast majority of HPV-related cancers, leading to them being seen as the most aggressive types.

This includes more than 70% of cervical cancer cases, with HPV 16 alone accounting for 50% of global cervical cancers.

Again, this doesn’t mean that HPV 16 and 18 will definitely lead to cancer as more than 90% of these infections go away within 6 to 18 months.

Cervical cancer isn’t the only form of cancer linked to HPV 16 and 18. An estimated 70% of anal cancers are linked to HPV 16 and 18, too.

It’s not just HPV 16 and 18 that are linked to cervical cancer. Eight other types have also been found in cervical cancer cases: 31, 33, 35, 45, 51, 52, 56 and 58.

There are fewer statistics relating to these types. HPV 31 is closely linked to HPV 16 but, according to research, it’s only responsible for 4% of global cervical cancers.

Studies have also found that HPV 31, 33, 52, and 58 present more of a risk of CIN 2 than HPV 18, which is when moderately atypical cells are found on the surface of the cervix. This can become cancerous if left untreated.

Finally, HPV 45 has been found to be more common in invasive cervical cancer cases along with types 16 and 18.

Currently, there isn’t much research on HPV type 39 and its link to cancer.

In one Spanish study, type 39 was found to be a key risk factor for anal cancer in men who have sex with men and who are HIV-positive.

The same study also noted HPV 39 put HIV-positive men who have sex with other men at a higher risk of a precancerous condition called anal intraepithelial neoplasia.

Closely related to HPV 18, HPV 59 is another risk factor for developing cervical cancer along with oropharyngeal cancer, which affects the throat. Compared with other types, there aren’t strong statistics for this strain of HPV.

It has also been noted in people with Bowen’s disease, which is an early and often easily treatable form of skin cancer.

Though there is some link between HPV 59 and anal cancer as well, it’s considered relatively weak.

An HPV infection will only turn into cancer if the infection is ongoing and remains within the body for a long time.

However, other than cervical cancer, there aren’t screening tests for cancers linked to HPV. So it’s vital to consult a healthcare professional if you’re worried about anything or have any unusual symptoms.

Some symptoms to be aware of include but aren’t limited to:

  • lumps in the mouth, throat, neck, or genital region
  • vaginal or anal bleeding
  • pain during sex
  • pain in the lower back, lower stomach, or around the anus
  • incontinence
  • sore throat

Healthcare professionals can treat many HPV-related cancers successfully if diagnosed early on.

Lauren Sharkey is a U.K.-based journalist and author specializing in women’s issues. When she isn’t trying to discover a way to banish migraine headaches, she can be found uncovering the answers to your lurking health questions. She has also written a book profiling young female activists across the globe and is currently building a community of such resisters. Catch her on Twitter.