Herpes is a sexually transmitted infection (STI) caused by the herpes simplex virus (HSV), which can result in painful sores or blisters on the genitals, mouth, or other areas of the body. There are two types of herpes simplex viruses: HSV-1, which generally causes oral herpes, and HSV-2, which commonly leads to genital herpes. Antiviral medications can help control symptoms, minimize the frequency of outbreaks, and reduce the risk of spreading the virus.