HPV (human papillomavirus) is a very common family of over 200 viruses. Some types (strains) of genital HPV can spread through vaginal, anal, or oral sex. They can cause abnormal changes (dysplasia) in the cells of a woman's cervix or vagina, or a woman's or man's anus. Depending on the strain of infection, these cellular changes can lead to cervical or anal cancer if not treated.
Also some strains of HPV can cause genital warts. These affect the moist tissues of the genital area. They may be too small to be seen. Or they may be small, flesh-colored bumps. Or cauliflower-like lesions.
HPV is the most common type of sexually transmitted infection (STI) in the United States. Many people carry HPV, but it often has no symptoms. The virus may first be found when signs of dysplasia or warts are found during a Pap test. Although the preferred method of testing for women is the HPV test when available.