Genital Herpes Genital herpes is a common sexually transmitted infection caused by the herpes simplex virus, usually HSV-2, but sometimes HSV-1. HSV-1 is commonly associated with cold sores, but it can also cause genital outbreaks through oral-genital contact. A genital herpes outbreak can cause painful sores, blisters, burning, itching, tingling, or discomfort in the genital or anal area. Some people have obvious outbreaks, while others have very mild symptoms or no symptoms