Understanding Your Laboratory Test: A Guide for Patients
This blood test checks for antibodies against Borrelia burgdorferi, the bacteria that causes Lyme disease, transmitted through tick bites.
{"Detects IgM (early infection) and IgG (later infection) antibodies in blood","Used to confirm Lyme disease diagnosis after a tick bite or characteristic symptoms","Antibodies take 1-2 weeks (IgM) and 4-6 weeks (IgG) to develop after infection","A positive result means you have been exposed to the bacteria, but doesn't always mean active infection","Testing is usually done in two stages: screening followed by confirmatory testing"}
Key facts at a glance
- LOINC
- 22131-7
- Short code
- LYMEAB
- Synonyms
- B burgdor IgG+IgM Ser Ql
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) - Tiger top; Red top tube acceptable
- Units
- N/A
- Ref low
- 2
- Ref high
- 4
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- Enzyme Immunoassay (EIA) with reflex to Western Blot confirmation; Two-tiered testing algorithm per CDC recommendations
- CPT
- 86618
- SNOMED
- 415625003
- Specimen volume
- 1-2 mL serum (minimum 0.5 mL)
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
This test is a laboratory analysis, most often performed on a small sample of your blood, urine, or other body material, that helps your healthcare provider evaluate how well your body is working and look for possible signs of illness.
The Borrelia burgdorferi IgG+IgM antibody test is a blood test that detects whether your immune system has produced antibodies against the bacteria that causes Lyme disease. Lyme disease is an infection transmitted through the bite of infected black-legged ticks (deer ticks). The test looks for two types of antibodies: IgM antibodies, which appear early in infection and indicate recent exposure, and IgG antibodies, which develop later and indicate a later stage of infection or past exposure.
Your doctor may order this test as part of a routine checkup, to help find the cause of symptoms you are having, to monitor an ongoing medical condition, to screen for certain health risks, or to see how well a treatment is working over time.
Your healthcare provider may order this test if you have been bitten by a tick or are experiencing symptoms suggestive of Lyme disease. Early symptoms often include a characteristic "bull's-eye" rash (erythema migrans), fever, headache, fatigue, and muscle aches. If left untreated, the infection can spread to joints, the heart, and nervous system. This test helps confirm whether your symptoms are due to Lyme disease.
Your results are compared with established reference ranges. Values within the normal range generally suggest that no abnormality was found, while results that are higher or lower than expected may point to a condition that needs closer attention. Always review your specific results with your healthcare provider, who can explain what they mean for your overall health.
Results are typically reported as positive or negative for IgG and IgM antibodies. A positive IgM result with negative IgG may indicate early infection. Positive IgG with or without positive IgG may indicate later or past infection. However, it's important to note that antibodies can remain in your blood for months or even years after treatment. Your healthcare provider will interpret results alongside your symptoms, exposure history, and timing of testing.
Reference range
Negative: No antibodies detected. Positive: Antibodies to Borrelia burgdorferi detected, suggestive of past or current infection. Equivocal results require repeat testing in 2-4 weeks or Western Blot confirmation.N/A
No fasting required. No special patient preparation needed. Sample should be collected before antibiotic therapy when possible, though antibodies may persist post-treatment.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used for diagnosing Lyme disease. The presence of IgM antibodies suggests early infection (within 4-6 weeks of tick exposure), while IgG antibodies typically develop 4-6 weeks after infection and may persist long-term. A single positive test does not always indicate active disease—confirmation with additional testing (such as Western blot) may be needed. Early detection and treatment with antibiotics are crucial for preventing complications such as arthritis, cardiac issues, or neurological problems.
Frequently asked questions
How is the test performed?
Do I need to fast before this test?
When should I be tested after a tick bite?
Can the test give false results?
What happens if my test is positive?
Sources
- 1
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- 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 15, 2026. · Read our editorial policy