Viral warts are due to an infection by the human papillomavirus (HPV). There are more than 100 HPV subtypes that are known to lead to different presentations with warts on the hands being one of them.
HPV is spread by direct skin to skin contact or auto-inoculation where the virus is spread to another part of the skin if a wart is being scratched or picked.
Warts on the hands are usually not STD related whereas anogenital warts are considered a STD as they are spread via sexual contact.
Most people leave their warts alone as they may not find them bothersome and treatment can be more uncomfortable than the wart itself. Small warts may even resolve on their own.
Treatment options for warts include topical treatments, cryotherapy (spraying liquid nitrogen gas to freeze it) or electrosurgery.
Speak to your doctor if you have a wart that you are worried about or is keen to have them removed so that he/she can advise you better.