Herpes tests are done to seek out the herpes simplex virus (HSV). An HSV infection can cause small, painful sores that appear as if 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 one outbreak of sores, but in many cases the person will have more outbreaks.
There are two sorts of HSV.
HSV type 1 causes cold sores (also called fever blisters) on the lips. HSV-1 is usually spread by kissing or by sharing eating utensils (such as spoons or forks) when sores are present. HSV-1 also can cause sores round the genitals.
HSV type 2 causes sores within the genital area (genital herpes), like on or round the vagina or penis. HSV-2 also causes the herpes infection seen in babies who are delivered vaginally in women who have herpes genitalis . HSV-2 is usually spread by sexual contact. HSV-2 can sometimes cause mouth sores.
In rare cases, HSV can infect other parts of the body, like the eyes and therefore the brain.