Herpes Blood Test (HSV-1 & HSV-2 IgG & IgM Antibodies)

This blood test screens for antibodies to herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), the viruses that cause cold sores and genital herpes. It is suitable for anyone who wants to know whether they have been exposed to either virus, including people with no symptoms, those with a history of cold sores or genital lesions, and individuals in new relationships who wish to make informed decisions about their sexual health. It is also used when a doctor needs to distinguish between the two virus types, since the pattern of antibody response can help clarify which virus is present.

The test detects two classes of antibodies: IgG, which usually indicates past or current infection, and IgM, which can appear early after exposure. Because IgM can sometimes be positive in other situations, results are interpreted alongside your clinical history. A simple blood sample is all that is required, and no special preparation is needed.

HSV-1 (Herpes Simplex Virus Type 1)
- HSV-1 IgG: indicates past or current infection with HSV-1, the virus most commonly associated with cold sores.
- HSV-1 IgM: may be present during a recent or active infection, though it is not specific on its own.

HSV-2 (Herpes Simplex Virus Type 2)
- HSV-2 IgG: indicates past or current infection with HSV-2, the virus most commonly associated with genital herpes.
- HSV-2 IgM: may be present during a recent or active infection, though it is not specific on its own.

Why it matters
Many people carry HSV-1 or HSV-2 without ever knowing, because symptoms can be mild or absent. Knowing your status helps you understand your own health, take steps to protect partners, and have informed conversations with your doctor about management and prevention. It also avoids unnecessary worry when symptoms have another cause, and supports timely treatment if outbreaks occur.