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Herpes Simplex Virus 1 Immunoglobulin G Antibody (Serum/Plasma)

Published: August 9, 2026Updated: August 16, 2026

This test measures the presence of antibodies against Herpes Simplex Virus 1 (HSV-1) in your blood. These antibodies indicate whether your immune system has been exposed to HSV-1, which causes cold sores and can also affect other parts of the body.

Quick summary

["This test helps determine past exposure to HSV-1, not whether you currently have an active infection."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
42507-4
Short code
HSV1 IgG CSF Ql
Synonyms
HSV1 IgG CSF Ql
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

What This Test Measures

Herpes Simplex Virus 1 (HSV-1) is a virus that can cause cold sores and other infections. Once you are infected, your body produces antibodies as part of your immune response. This test detects these antibodies in your blood, showing if you have had exposure to HSV-1 at some point.

Why It’s Done

Doctors may order this test if you have symptoms of HSV-1 infection (such as cold sores), if you have a history of cold sores, or if you are being evaluated for recurrent infections that might be linked to HSV-1.

How It’s Done

A blood sample is taken from a vein in your arm. The blood is then sent to a lab for testing using an immunoassay method to detect HSV-1 antibodies.

What to Expect Before or After

There are no special preparations needed for this test. You may experience mild discomfort or bruising at the injection site, but this usually goes away quickly. If you have a bleeding disorder or take blood-thinning medications, let your healthcare provider know before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HSV-1 IgG Antibody

Frequently asked questions

Can this test tell me if I currently have an active HSV-1 infection?
No, this test only shows if you have had past exposure to HSV-1 by detecting antibodies. For diagnosing an active infection, your healthcare provider may use other tests or clinical evaluation.
What does a high or low antibody level mean?
A high level of HSV-1 IgG antibodies suggests previous exposure to the virus. A low or undetectable level means either you have never been exposed or the test was taken too soon after exposure. Levels do not directly indicate the severity or frequency of past infections.
Does this test require fasting?
No fasting is required for this blood test.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy