The different strains of hpv

There are more than a 100 HPV strains although about only 40 of them are dangerous to health. 

A person may be infected with multiple strains at any time. 

Strains are identified by a number and fall into the two categories: high-risk and low-risk. 

High-risk strains

Most HPV infections go away on their own without any treatment however sometimes the HPV can persist and cause abnormal changes to the cells. These cells may develop into cervical cancer over the course of many years. 

Some HPV types are high-risk because they have the potential to cause cervical cancer. There are around 40 high risk strains including the most notorious strains 16 and 18, which cause the majority of cervical cancer.

High risk strains can also cause other cancers in the throat, tongue, and tonsils.  

Low-risk strains

Low risk HPV types may cause mild pap test abnormalities or genital warts. HPV strains 6 and 11 are responsible for about 90% of genital warts. Other HPV strains may even infect the skin of the fingers, hands or face. 

Some low risk strains may cause abnormal changes to cells on the cervix but they are not pre-cancerous. 

Resources:

https://nyulangone.org/conditions/human-papillomavirus-in-adults/types

https://www.researchgate.net/figure/Phylogenetic-and-Epidemiologic-Classification-of-HPV-Types_tbl5_10914623

Table citation: Munoz, Nubia & Bosch, F. & Sanjosé, Silvia & Castellsagué, Xavier & Shah, Keerti & Snijders, Peter & Meijer, Chris. (2003). Epidemiologic Classification of Human Papillomavirus Types Associated with Cervical Cancer. The New England journal of medicine. 348. 518-27. 10.1056/NEJMoa021641.