Herpes tests are done to find the herpes simplex virus (HSV). An HSV infection can cause small, painful sores that look like blisters on the skin or the tissue lining (mucous membranes) of the throat, nose, mouth, urethra, rectum, and vagina. A herpes infection may cause only a single outbreak of sores, but in many cases the person will have more outbreaks.
There are two types of HSV.