How to Test for Lyme Disease: Diagnosis and Types of Tests Explained

Testing does not always confirm Lyme disease.
Results depend on timing and immune response.
Clinical diagnosis remains essential.

Types of Lyme disease tests vary widely in what they measure and how reliable they are in different stages of infection.

No laboratory test can diagnose every case of Lyme disease. Understanding when to test—and what each test can and cannot detect—can help explain why some patients receive negative results despite compatible symptoms.

While laboratory testing can support diagnosis, Lyme disease is often best identified clinically based on symptoms, exposure history, and physical findings.

This becomes clearer when reviewing Lyme disease test accuracy, where timing and immune response significantly affect results.

Quick answer: Lyme disease is usually tested with blood tests that detect antibodies to Borrelia burgdorferi. Common tests include ELISA or EIA, Western blot, C6 peptide assays, standard two-tier testing, modified two-tier testing, and, in selected situations, PCR. However, early tests may be negative because antibodies can take weeks to develop.

How to test for Lyme disease depends on the stage of illness and the type of test being used. Common Lyme disease blood tests include ELISA, Western blot, C6 peptide assays, PCR testing, and two-tier antibody testing recommended by the CDC.

Here’s how these tests actually work in clinical settings.

How do doctors test for Lyme disease?

Doctors diagnose Lyme disease using a combination of medical history, physical examination, tick exposure, symptoms, and laboratory testing when appropriate.

Blood tests such as ELISA and Western blot detect antibodies rather than the Lyme bacteria itself. This makes timing an important factor when interpreting test results.

In patients with a classic erythema migrans rash, treatment is often started without waiting for laboratory confirmation because antibody tests may still be negative.

Laboratory testing should support, rather than replace, clinical diagnosis. Brown and colleagues emphasized that serologic tests should not be used as the primary basis for making diagnostic or treatment decisions, especially early in the illness when sensitivity is low.²

How Lyme disease is diagnosed

1. Review symptoms and possible tick exposure.
2. Perform a physical examination.
3. Look for an erythema migrans rash or other clinical signs.
4. Order ELISA or EIA testing when appropriate.
5. Confirm positive or equivocal results with recommended second-tier testing.
6. Interpret laboratory results together with clinical findings.

Clinical Diagnosis Remains Essential

Lyme disease cannot always be confirmed with a single test.

Diagnosis often depends on a physician’s ability to recognize patterns, including tick exposure and evolving symptoms.

Testing is often expected to provide clear answers, even when it cannot.

This issue is frequently seen in delayed Lyme disease diagnosis, where patients may test negative early in illness.

When should you test for Lyme disease?

Testing too soon after a tick bite may produce a false-negative result because antibodies often take several weeks to develop.

Testing immediately after a tick bite is generally not recommended in people without symptoms because antibodies have usually not yet formed.

Patients with an erythema migrans rash may be diagnosed clinically before blood tests become positive.

Serologic testing may be more useful later in illness, when antibody responses have had more time to develop.

Why Lyme Disease Tests Can Be Inaccurate

Test accuracy depends on several factors:

• Stage of infection
• Timing of immune response
• Prior antibiotic treatment
• Variability in Borrelia strains

Antibodies may not appear until weeks after infection.

Early testing may therefore be negative, even in infected patients.

This limitation is explained further in why early Lyme tests may be negative.

Additionally, the bacteria are not always present in the bloodstream, making direct detection difficult.

Most Common Types of Lyme Disease Tests

Several laboratory tests are used in clinical practice:

• ELISA or EIA
• Western blot
• Two-tier antibody testing
• Modified two-tier testing
• C6 peptide ELISA
• PCR testing
• Culture testing

Each test evaluates a different aspect of infection, and each has limitations.

ELISA Lyme Disease Test

The ELISA test is typically used as the first screening tool.

It detects antibodies to Borrelia burgdorferi.

However, sensitivity is lowest during the first several weeks after infection because antibody production is still developing.

This means many infected patients may test negative early in the illness.

Western Blot Lyme Test

The Western blot identifies specific antibody bands reacting to Borrelia proteins.

CDC criteria include:

• IgM: 2 of 3 bands (23, 39, 41 kDa)
• IgG: 5 of 10 bands

While more specific than ELISA, Western blot testing can still miss cases and may be difficult to interpret.

For a deeper explanation, see Save the two-tier Lyme disease test?

How to interpret Lyme disease test results

Interpreting Lyme disease test results can be difficult because antibody bands may appear differently depending on the stage of infection and the patient’s immune response.

Some patients with symptoms consistent with Lyme disease may not meet strict CDC surveillance criteria despite clinical evidence of infection.

Western blot bands such as 23, 39, and 41 kDa are commonly discussed because they may reflect exposure to Borrelia burgdorferi.

This is one reason Lyme disease bands explained online often create confusion for patients trying to understand whether their results are meaningful.

What do Lyme disease antibody bands mean?

Western blot bands represent antibodies directed against different Borrelia proteins rather than the bacteria itself.

Individual bands should not be interpreted in isolation because antibody patterns can change over time and interpretation depends on the clinical setting.

Two-Tier Lyme Testing

The standard CDC approach uses two-tier testing:

• ELISA or EIA first
• Western blot if the first test is positive or indeterminate

This system may miss cases because both tests must be positive.

Traditional two-tier testing was designed to improve specificity, but early Lyme disease can still be missed because the test depends on antibody production.

Modified Two-Tier Testing

Some laboratories now use modified two-tier testing, also known as MTTT. This approach replaces the Western blot with a second enzyme immunoassay.

Modified two-tier testing may improve sensitivity in early Lyme disease while maintaining high specificity, although performance varies among commercial assays.

A 2024 study comparing two modified two-tier algorithms found that different MTTT platforms performed differently. The authors reported that MTTT methods may improve detection of some early cases, but early false-negative results and assay variability still remain important limitations.³

C6 peptide Lyme test

The C6 peptide ELISA detects antibodies against a conserved Borrelia protein and is used in some Lyme disease testing strategies, including some modified two-tier testing algorithms.

Like other antibody tests, the C6 peptide test performs better after the immune response has had time to develop.

PCR Lyme Test

PCR testing detects bacterial DNA rather than antibodies.

However, sensitivity is often low in routine practice.

PCR is not routinely recommended on blood for early Lyme disease because bloodstream infection is typically brief and bacterial DNA levels are low.

PCR testing is generally more useful for certain clinical specimens, such as synovial fluid in Lyme arthritis, than for routine blood testing because Borrelia is often not present in the bloodstream.

Culture Testing

Culturing Borrelia burgdorferi is difficult due to slow growth and low bacterial presence in blood.

Newer culture methods are under investigation but are not widely used in routine clinical practice.

Are newer Lyme disease tests being developed?

Researchers are evaluating newer diagnostic approaches, including multiplex antibody assays designed to improve detection during the earliest weeks of infection.

A 2025 study evaluated a multiplexed single-tier Lyme Detect ELISA and found that it detected some clinically diagnosed erythema migrans cases that were negative by standard two-tier testing, while maintaining high specificity in the study sample.⁴

Although promising, newer tests require additional validation before replacing currently recommended testing strategies.

Testing for Lyme Disease Co-Infections

Testing for co-infections such as Babesia, Bartonella, Ehrlichia, and Anaplasma can also be challenging.

Laboratory findings may be subtle and easily missed.

Because of this, clinicians often rely on pattern recognition and clinical judgment.

For more, see the Lyme disease co-infections guide.

Can routine blood work show Lyme disease?

Routine blood tests such as a complete blood count or chemistry panel do not diagnose Lyme disease.

These tests may show nonspecific abnormalities or help evaluate other medical conditions, but specific Lyme disease testing must be ordered when clinically appropriate.

Why This Matters

Testing can support diagnosis, but it cannot replace clinical judgment.

Relying solely on laboratory results may lead to missed diagnoses and delayed care.

This reflects a broader issue explored in why Lyme disease tests the limits of medicine.

Frequently Asked Questions

Can Lyme disease tests be negative even if someone is infected?

Yes. Antibodies may take weeks to develop, leading to false-negative results early in infection.

What are the most common Lyme disease tests?

ELISA or EIA and Western blot are among the most commonly used tests. Some laboratories now use modified two-tier testing, which uses two antibody-based immunoassays instead of Western blot.

Can Lyme disease be diagnosed without a positive test?

Yes. Diagnosis is often clinical, based on symptoms, exposure risk, and physical findings such as an erythema migrans rash.

What tests confirm Lyme disease?

No single test confirms Lyme disease in every case. Physicians often combine laboratory testing with clinical evaluation, exposure history, symptoms, and physical findings.

What is the most accurate test for Lyme disease?

No Lyme disease test is perfect. Accuracy depends on timing, immune response, and stage of illness. Early infections are more likely to produce false-negative results.

What blood test is used for Lyme disease?

The most commonly used blood tests are enzyme immunoassays, also called ELISA or EIA tests. If the first test is positive or equivocal, confirmatory testing may include Western blot or a modified two-tier testing algorithm.

When is the best time to test for Lyme disease?

Testing is more likely to be positive after antibodies have had time to develop, often several weeks after infection. Testing too early may produce a false-negative result.

Can antibiotics affect Lyme disease test results?

Prior antibiotic treatment may affect the immune response and complicate interpretation of Lyme disease test results, especially if treatment occurs early in the illness.

Can Lyme disease show up in routine blood work?

No. Routine blood tests such as a complete blood count or chemistry panel do not diagnose Lyme disease. Specific Lyme antibody testing must be ordered when clinically appropriate.

Clinical Takeaway

Types of Lyme disease tests provide useful information, but they are not definitive in every case.

Clinical judgment remains essential, particularly when symptoms and exposure history suggest infection.

Early Lyme disease testing may be falsely negative, while later testing may be more useful as antibodies develop.

Understanding how to test for Lyme disease requires recognizing both the strengths and limitations of current laboratory testing.

Related Articles

These related articles explore Lyme disease diagnosis, testing limitations, neurologic symptoms, co-infections, and persistent illness patterns.

Lyme Disease Misdiagnosis
Lyme Disease Co-Infections
Save the Two-Tier Lyme Disease Test?
Lyme Disease Symptoms Guide
Post-Treatment Lyme Disease Syndrome

References

1. Branda JA, Steere AC. Laboratory diagnosis of Lyme disease. Clin Microbiol Rev. 2021;34(2):e00018-19.
2. Brown SL, Hansen SL, Langone JJ. Role of serology in the diagnosis of Lyme disease. JAMA. 1999;282(1):62-66. doi:10.1001/jama.282.1.62.
3. Landry ML, Hassan S, Rottmann BG, et al. Performance of two modified two-tier algorithms for the serologic diagnosis of Lyme disease. J Clin Microbiol. 2024;62(5):e00139-24. doi:10.1128/jcm.00139-24.
4. Hickman AF, Weber AF, Horn EJ, Gwynne PJ. The multiplexed single-tier InBios Lyme Detect Multiplex ELISA is more sensitive than standard two-tier tests in the early stages of Lyme disease. J Clin Microbiol. 2025;63(11):e00629-25. doi:10.1128/jcm.00629-25.

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Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention