Human papillomavirus (HPV) is a group of viruses that cause common skin warts. Papillomas are warts. Some types of HPV are sexually transmitted. Of those types, there are two categories, low-risk and high-risk:

• Low-risk. Can cause genital warts, but do not cause precancerous changes on the cervix. Most people with low-risk types of HPV do not know they are infected because they do not get warts. Warts can form weeks, months or years after sexual contact with a person infected with HPV. Genital warts are most commonly associated with HPV types 6 and 11.
  
  
• High-risk. Can cause changes that may lead to precancerous changes in the cervix if untreated. Having high-risk HPV is not the same as having cervical cancer. Usually, high-risk HPV types cause no health problems and disappear on their own. High-risk types that persist, however, are a major risk factor for cervical cancer. Sexually transmitted, high-risk HPVs include types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 69 and possibly a few others.