Understanding Your Medical Test: A Complete Patient Guide to Diagnostic Testing and What to Expect
This blood test checks for antibodies against Borrelia burgdorferi, the bacterium that causes Lyme disease, to determine if you have been infected.
{"The test detects IgM, IgG, and IgA antibodies that your immune system produces in response to Lyme disease bacteria","IgM antibodies typically appear first (2-4 weeks), followed by IgG (4-6 weeks), and IgA may indicate later or chronic infection","A positive result means you have been exposed to the bacteria, but does not always mean you have active Lyme disease","Testing is usually done in two stages: an initial screening test followed by a confirmatory Western blot test","Early detection and treatment with antibiotics is important for recovery"}
Key facts at a glance
- LOINC
- 51747-4
- Short code
- LYME-AB
- Synonyms
- B burgdor IgA+IgG+IgM Ser IA-Imp
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top vacutainer tube; sterile collection tube acceptable
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Immunoassay (Enzyme-linked immunosorbent assay - ELISA or Chemiluminescence Immunoassay - CLIA) for detection and interpretation of IgA, IgG, and IgM antibodies against Borrelia burgdorferi
- CPT
- 86618
- SNOMED
- 415450008
- Specimen volume
- 1-2 mL of serum (minimum 0.5 mL)
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or lower): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 24–72 hours
- Order
- routine
What is this test, and why might my healthcare provider have recommended it as part of my medical care?
The Borrelia burgdorferi antibody test is a blood test that detects three types of antibodies (IgM, IgG, and IgA) produced by your immune system in response to infection with the bacteria Borrelia burgdorferi, which causes Lyme disease. This test uses an immunoassay technique to measure whether your blood contains these specific antibodies.
How does the test work, and what exactly does it measure or examine inside my body during the procedure?
When your body is infected with Lyme disease bacteria, your immune system produces specific antibodies to fight the infection. This test looks for these antibodies in your blood serum. IgM antibodies are usually the first to appear (typically 2-4 weeks after infection), IgG antibodies develop later (4-6 weeks), and IgA antibodies may appear in later stages of infection. The timing of antibody appearance is why the test results are interpreted differently depending on how long you may have been infected.
Why is this test performed, which symptoms or conditions can it help detect, and how do doctors use the results?
Your healthcare provider may order this test if you have symptoms suggestive of Lyme disease, especially if you have been exposed to areas where Lyme disease is common (such as forests or areas with tall grass). Common symptoms include a characteristic 'bull's-eye' rash (erythema migrans), fever, headache, fatigue, and muscle aches. The test is also used to confirm Lyme disease infection in patients with symptoms and known tick exposure.
What do the results mean, what is considered a normal range, and how will my doctor discuss the findings with me?
Results are typically reported as positive, negative, or equivocal for each antibody type (IgM, IgG, and IgA). A positive IgM result with symptoms suggests early infection. Positive IgG suggests later or past infection. However, a positive test does not always mean you have active Lyme disease—it indicates exposure to the bacteria. Your healthcare provider will interpret results together with your symptoms, physical findings, and exposure history. Sometimes a follow-up test called Western blot is used to confirm results.
What happens during the test step by step, how long does it usually take, and will I need any special preparation beforehand?
A healthcare professional will draw a blood sample from a vein in your arm using a small needle. You may feel a brief sting or pinch. The blood is collected into a tube and sent to a laboratory for analysis. The test requires no special preparation, and you can resume normal activities immediately after the blood draw.
Reference range
Interpretive result: Negative, Equivocal, or Positive for IgA, IgG, and IgM antibodies to Borrelia burgdorferi. Standard two-tier testing (STTT) recommended: positive or equivocal immunoassay results should be confirmed with Western blot or modified two-tier testing (MTTT). Reference ranges vary by assay manufacturer.N/A
No special patient preparation required. Fasting is not necessary. Patients should inform the laboratory of any current antibiotic therapy, immunocompromised status, or recent vaccination history, as these may influence antibody response.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to diagnose Lyme disease, a tick-borne illness caused by Borrelia burgdorferi bacteria. Early detection is crucial because prompt antibiotic treatment (typically doxycycline, amoxicillin, or cefuroxime) is highly effective in eliminating the infection and preventing complications such as joint pain, neurological problems, and heart issues. The test helps differentiate between early and late-stage infection based on which antibodies are present—IgM suggests early infection, while IgG indicates later or past infection. In areas where Lyme disease is endemic, this test is an important tool for confirming clinical diagnosis, especially when patients present with the characteristic erythema migrans rash or unexplained flu-like symptoms after tick exposure.
Limitations include the fact that antibodies may not be detectable in the first few weeks of infection (the 'window period'), and the test cannot distinguish between past exposure and current active infection. False positives can occur in patients with other conditions (such as syphilis, Rocky Mountain spotted fever, or certain autoimmune diseases), which is why confirmatory testing is sometimes needed. Additionally, some patients may remain seropositive for months or years after successful treatment, so the test should not be used to monitor treatment response in most cases.
Frequently asked questions
Do I need to fast before this test?
How long does it take to get results?
Can the test be positive if I was successfully treated years ago?
What if my test is negative but I still have symptoms?
Is there a single best test for Lyme disease?
Can I get Lyme disease more than once?
Sources
- 1
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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