Human Papillomavirus

According to the National Institute of Health, human papillomavirus (HPV) is the most common sexually transmitted disease, with approximately 20 million Americans infected, and 6 million new infections each year. Most people don't know that they are infected and the virus can go away on its own. However, it can become symptomatic, even years after exposure, most commonly with genital warts in men and women and changes to the cells of the cervix in women. These cell changes, called dysplasia, can develop into cervical cancer if left in place. It can be detected with a Pap smear, which is why having an annual gynecological exam is so important.
There is now a vaccine against HPV, available to women aged 11 to 26 or so.