Quick answer

Lyme disease testing looks for antibodies to the bacteria spread by tick bites. It is done in two steps — a screening test, then a confirmatory blot — because a single test is not reliable enough. Timing matters: too early and the test can miss the infection.

What is Lyme Disease Test?

Lyme disease is caused by Borrelia bacteria transmitted by certain tick bites. The immune system makes antibodies in response, but they take weeks to appear — so testing too soon after a bite can be falsely negative. Standard practice uses a two-step approach: an initial antibody screen, and if that is positive or equivocal, a confirmatory immunoblot. The test is interpreted alongside symptoms and tick exposure history.

Typical reference interval: Reported as negative, positive, or equivocal at each step. Early infection (first weeks) may test negative even with true disease, so a repeat after a few weeks is common when suspicion remains high.. Laboratories differ — the interval printed on YOUR report always governs.

If your Lyme Disease Test is high

Common reasons Lyme Disease Test runs above the reference interval:

  • Current or past Lyme infection — antibodies indicate the immune system has met the bacteria — the core reason for a positive result
  • Two-step confirmation — a positive screen is only meaningful after the confirmatory blot agrees — the pair is the real result
  • Persistent antibodies after treatment — antibodies can remain for years after successful treatment, so a positive test does not always mean active disease

If your Lyme Disease Test is low

Common reasons Lyme Disease Test runs below the reference interval:

  • No exposure — a negative result is the expected finding for most people — no evidence of Lyme antibodies
  • Testing too early — in the first weeks after a bite, antibodies may not have formed yet — a false-negative window
  • Antibiotic treatment before testing — early treatment can blunt the antibody response and affect results

Symptoms worth knowing

The classic early sign is an expanding rash (sometimes a bullseye) at the bite site, often with fever, fatigue, and aches. Later disease can bring joint pain, nerve symptoms, and heart-rhythm issues. Testing supports the diagnosis but never replaces the clinical picture.

What usually happens next

  1. Lyme testing is interpreted with symptoms and tick-exposure history — a number alone is not a diagnosis
  2. A negative test in the first weeks of suspected illness should be repeated rather than treated as final
  3. If symptoms and testing point to Lyme, treatment is clinician-directed antibiotics — early treatment works best

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Related result guides

Frequently asked questions about Lyme Disease Test results

I was bitten by a tick and tested negative — am I clear?

Not necessarily. Antibodies take weeks to develop, so a test right after the bite can miss a true infection. If you have symptoms or a rash, your clinician may repeat the test later or treat based on the clinical picture.

Can Lyme tests stay positive after treatment?

Yes — antibodies often persist for years after successful treatment. That is why a positive test alone does not prove active infection; symptoms and timing guide interpretation.

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