Herpes Simplex Virus Type 1 IgM Antibody (Serum)
This test measures the presence of Immunoglobulin M (IgM) antibodies against Herpes Simplex Virus Type 1 (HSV-1) in your blood. IgM antibodies are typically produced shortly after infection and can help identify recent exposure to the virus.
["IgM antibodies to HSV-1 may indicate a recent infection with the virus that causes cold sores or genital herpes."]
Key facts at a glance
- LOINC
- 41149-6
- Short code
- HSV1+2 IgM Ser Ql
- Synonyms
- HSV1+2 IgM Ser Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Does This Test Measure?
IgM antibodies are a type of antibody your immune system produces in response to an infection. In this test, we detect whether you have developed IgM antibodies against HSV-1, which suggests you may have been recently infected with this virus. Unlike IgG antibodies, which can persist longer, IgM levels tend to decrease over time as your body clears the infection.
Why Might You Need This Test?
Your healthcare provider may order this test if you have symptoms like sores, pain, or lesions that could be caused by HSV-1, especially if you have no known history of herpes. It can also be used to confirm a recent infection in people with no prior exposure or if symptoms are unclear.
What Does a Positive Result Mean?
A positive result means your blood contains IgM antibodies to HSV-1, which strongly suggests you were recently infected. This does not necessarily mean you are currently experiencing symptoms, as some people may not show signs of infection even if infected. Follow-up testing with IgG antibodies may be needed to understand the timeline of your infection.
What Does a Negative Result Mean?
A negative result means your blood did not contain detectable IgM antibodies to HSV-1 at the time of testing. This could mean you either have never been infected, are not currently infected, or the infection was so recent that IgM antibodies were not yet detectable.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
IgM antibodies to HSV-1 are useful for diagnosing recent infections, especially in cases where symptoms are mild or unclear. However, they are not definitive for diagnosing herpes, as other conditions can cause similar symptoms. IgG antibodies (if tested) can provide additional context about past exposure. If you have symptoms, it’s important to discuss them with your healthcare provider to determine the best course of action, which may include additional testing or treatment.
Short name
IgM Antibody to HSV-1
Frequently asked questions
When might I need to retest?
What if my IgM result is positive but I have no symptoms?
Can I get this test at home?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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