Lyme Evidence Sheet
Reviewed 2026-07-24What do IgM, IgG, and “overall result” mean?
IgM and IgG are antibody terms that need to be read with the testing sequence, timing, and the laboratory’s final interpretation.
What the evidence says
- CDC/APHL guidance describes different interpretation considerations for IgM and IgG results.
- Antibody results are interpreted with illness duration and the complete two-tier sequence.
What this can tell you
- Which terms are present in a report.
- Why the final overall interpretation matters more than an isolated marker.
What this cannot tell you
- When infection began from one marker alone.
- Whether a single marker proves active infection.
A useful question for your clinician
What is the laboratory’s overall interpretation, and how does the timing affect the IgM or IgG wording?
Sources (2)
- Centers for Disease Control and Prevention. ‘Testing and Diagnosis for Lyme Disease.’ https://www.cdc.gov/lyme/diagnosis-testing/index.html. Accessed July 24, 2026. Open source ↗
- Centers for Disease Control and Prevention and Association of Public Health Laboratories. ‘Suggested Reporting Language, Interpretation and Guidance Regarding Lyme Disease Serologic Test Results.’ 2024. https://www.cdc.gov/lyme/media/pdfs/2024/05/Suggested-Reporting-Language-Interpretation-and-Guidance-Regarding-Lyme-Disease-Serologic-Test-Results.pdf. Open source ↗