The human papilloma virus (HPV) is a common group of viruses. Over 100 different types of HPV have been identified, and each is known by a number. HPV affects the skin and the mucosa (the moist membranes that line parts of the body, such as the insides of the mouth, throat and anus).
Some types of HPV are known to increase the risk of developing particular types of cancer and are known as high-risk HPVs. The types most often associated with cancer are types 16 and 18. High-risk HPVs can lead to abnormal changes in the cells, which is sometimes called dysplasia. Although dysplasia is not cancer, it's sometimes described as being pre-cancerous.
Other types of HPV can cause warts and verrucas. These may appear on different parts of the body, but are more commonly seen on the hands and feet, in the genital area and around the anus. The types of HPV that cause visible warts and verrucas are less clearly linked with cell changes that can increase the risk of cancer. They are known as low-risk HPVs.
This information is about the high-risk HPV types that can increase the risk of developing cancer.