Herpes Simplex Virus 1 Antibody, Qualitative (IgG)

The herpes simplex virus (HSV) antibody test measures proteins called antibodies that your immune system produces in response to an HSV-1 or HSV-2 infection. HSV-1 commonly causes cold sores around the mouth, while HSV-2 is more often linked to genital herpes, though either type can occur in either location. Because these antibodies remain in your blood for life, this blood test can show whether you have ever been exposed to the virus, even if you have never noticed any symptoms.

The test detects specific antibodies (IgG) produced by your immune system in response to HSV-1. These antibodies indicate that your body has encountered the virus at some point, often years ago, even if symptoms were mild or absent.

Your doctor may order this test if you have symptoms that could suggest a herpes infection, such as blisters or sores in the genital or mouth area, or if a current or past partner has been diagnosed with herpes. It can also be useful when sores have healed and a swab test is no longer possible, or when you want to know your infection status before starting a relationship, planning a pregnancy, or managing recurring symptoms.

Doctors may order this test if you have symptoms like fever blisters, recurrent cold sores, or if you’ve been exposed to someone with HSV-1. It can also be used in certain medical evaluations, such as for pregnant women to assess risk during delivery.

This test requires only a routine blood sample, so very little preparation is needed. You can usually eat and drink normally beforehand, and you should keep taking your regular medications unless your doctor tells you otherwise. A healthcare professional will draw a small amount of blood from a vein in your arm, a procedure that typically takes just a few minutes. Let your provider know if you take medicines that affect blood clotting or if you tend to feel faint during blood draws.

No special preparation is needed. You’ll provide a blood sample, typically drawn from your arm. The test is usually done in a lab and results are available within a few days.

A positive result means antibodies to HSV-1, HSV-2, or both were found in your blood, which indicates a past or current infection with that virus type. A negative result usually means you have not been exposed, although a very recent infection may not yet be detectable because antibodies can take several weeks to develop. Your doctor will interpret your result together with your symptoms, medical history, and any physical findings, and will discuss whether treatment, repeat testing, or steps to protect partners are needed.

A positive result means your body has produced antibodies against HSV-1, suggesting past exposure. A negative result means no detectable antibodies were found, but this does not rule out possible infection if tested too early after exposure.