How Often Is Lyme Disease Misdiagnosed?

Studies report misdiagnosis in different patient populations
Patient surveys document delayed diagnoses and prior conditions
Referral studies also identify Lyme disease overdiagnosis

How often is Lyme disease misdiagnosed? There is no single population-wide percentage. Studies reach different conclusions because they examine different groups of patients and define misdiagnosis differently.

Some studies investigate people who ultimately received a Lyme disease diagnosis after years of symptoms and multiple previous diagnoses. Other studies evaluate patients referred for presumed Lyme disease who were subsequently considered to have another explanation for their illness.

In a MyLymeData registry study of 3,903 participants, 72% reported receiving another diagnosis before Lyme disease was diagnosed.¹ By contrast, a study of 1,261 patients referred to an academic infectious diseases clinic for presumed Lyme disease found that 72.2% were classified by the clinic investigators as not having Lyme disease.²

These percentages describe different diagnostic problems and cannot be combined or interpreted as the overall Lyme disease misdiagnosis rate.

For a broader discussion of the diagnostic assumptions and testing limitations that may contribute to missed cases, see Why Lyme Disease Gets Missed, Misdiagnosed, or Dismissed.

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How often were patients diagnosed with another condition first?

Johnson and colleagues analyzed information reported by 3,903 individuals registered with MyLymeData.¹ Most participants described substantial delays before receiving a Lyme disease diagnosis.

More than half, or 51%, reported waiting more than three years for a diagnosis. A similar proportion, 54%, reported seeing five or more clinicians before Lyme disease was diagnosed.

Diagnostic delays were reported even though 45% of participants recalled developing early symptoms within days to weeks of tick exposure.

The authors reported that 37% of participants attributed the delay to false-negative laboratory results. Another 13% reported receiving positive results that were dismissed as false positives.

Testing may be negative during the early stage of infection because antibodies are not always detectable immediately. This early window period is discussed further in Why Early Lyme Disease Tests Can Be Negative.

What conditions were reported before Lyme disease?

In the MyLymeData study, 72% of participants reported receiving another diagnosis before being diagnosed with Lyme disease.¹

Reported prior diagnosis	Participants
Psychiatric disorder	52%
Fibromyalgia	43%
Chronic fatigue syndrome	42%

Although 52% reported having received a psychiatric diagnosis, only 18% identified psychiatric symptoms as being among their three worst symptoms.

These results do not establish that psychiatric disorders, fibromyalgia or chronic fatigue syndrome were incorrectly diagnosed in every participant. They describe the diagnoses participants reported receiving before Lyme disease was recognized.

What symptoms did participants report?

Neurologic-associated symptoms were among the three worst symptoms for 84% of MyLymeData participants. Fatigue was reported by 62%, while musculoskeletal-associated symptoms were reported by 57%.

Neurologic complaints included cognitive impairment, memory loss, impaired sleep, headaches, twitching, psychiatric manifestations and neuropathy. Cognitive impairment was reported by 30% of participants, while neuropathy was reported by 29%.

Musculoskeletal complaints included muscle aches and joint pain.

These symptoms are not specific to Lyme disease and may occur with several other conditions. However, their presence across multiple body systems may prompt clinicians to reconsider Lyme disease when the exposure history and course of illness are compatible. A broader overview is available in the Lyme Disease Symptoms Guide.

Another patient survey found long diagnostic delays

Fagen and colleagues conducted an online survey involving 986 respondents who identified as having Lyme disease or chronic Lyme disease.³

Among the 952 respondents who answered the question about diagnostic timing, the median interval between symptom onset and diagnosis was seven years. Among 958 respondents, the median number of doctors seen before diagnosis was 10.

Respondents described having symptoms attributed to stress, mental illness, normal aging or psychosomatic causes. Some also reported that positive blood tests, erythema migrans rashes or requests for Lyme disease testing had been dismissed.

These findings describe patient experiences rather than independently confirming that every reported interaction represented a missed Lyme disease diagnosis. Participants were recruited through patient-led online groups and nonprofit organizations, and the survey population was predominantly female and White.

Can Lyme disease also be overdiagnosed?

Yes. Misdiagnosis can also occur when symptoms from another condition are incorrectly attributed to Lyme disease.

Kobayashi and colleagues reviewed 1,261 patients referred or self-referred to a Johns Hopkins infectious diseases clinic because of a presumed Lyme disease diagnosis or concern about Lyme disease.²

Classification by referral clinic investigators	Patients
No Lyme disease	72.2%
Active or recent Lyme disease	14.6%
Remote history of Lyme disease	11.9%
Possible Lyme disease	1.3%

Among the 911 patients classified as not having Lyme disease, 83.9% had previously received antimicrobial treatment for Lyme disease or presumed coinfections.

This study cannot determine the rate of overdiagnosis among everyone evaluated for Lyme disease. It involved a selected population seen at one academic referral clinic, and many patients had prolonged or medically complex symptoms.

Nevertheless, the findings illustrate the need to consider other potential causes of fatigue, joint pain, muscle pain, cognitive difficulties and sleep disturbance.

Accurate diagnosis requires integrating the clinical history, exposure risk, physical findings, laboratory results and appropriate consideration of alternative diagnoses.

Does delayed diagnosis affect Lyme disease outcomes?

Delayed recognition may postpone appropriate treatment and allow the illness to progress before Lyme disease is considered.

In a 2007 article, Cameron examined the potential consequences of treatment delay in Lyme disease.⁴ The article reviewed studies and clinical observations involving patients whose diagnoses or treatment had been delayed.

One cited case series involved patients with Lyme disease confirmed by an enzyme-linked immunosorbent assay and at least five positive IgG Western blot bands. Thirty-two percent had experienced an average treatment delay of 1.8 years. Patients with delayed treatment were significantly more likely to fail their initial antibiotic treatment.

The article also discussed a study in which patients treated for neurologic Lyme disease were more likely than patients treated for erythema migrans to report persistent neuropsychiatric symptoms three years later.

A 2010 review further discussed diagnostic delays described in clinical studies, including treatment delays averaging two years among participants in a Lyme encephalopathy trial.⁵

These findings raise concern about the consequences of delay, but observational studies cannot prove that delayed treatment alone accounts for every persistent symptom. Disease stage, clinical presentation, previous treatment, coinfections and other medical conditions may also affect outcomes.

How should the misdiagnosis studies be interpreted?

The available studies cannot provide one universal Lyme disease misdiagnosis rate because they examined substantially different populations:

• The MyLymeData study evaluated members of a voluntary patient registry.
• The medical gaslighting study recruited respondents through patient organizations and online groups.
• The Johns Hopkins study evaluated a specialty referral population with presumed Lyme disease.
• The treatment-delay articles reviewed clinical studies, observational data and case series.

The similar 72% findings in the MyLymeData and Johns Hopkins studies describe opposite diagnostic pathways.

In MyLymeData, 72% reported receiving another diagnosis before Lyme disease. In the referral-center study, 72.2% were classified by the investigators as not having Lyme disease.

The two percentages should not be compared as though they measure the same outcome. They instead show that Lyme disease can be missed in some patients and assigned incorrectly in others.

Editor’s note: MyLymeData is a project of LymeDisease.org, a grassroots nonprofit organization that supports the interests of Lyme disease patients and conducts patient-centered research.

Frequently Asked Questions

How often is Lyme disease misdiagnosed?

There is no reliable population-wide percentage. In a voluntary registry of 3,903 participants, 72% reported receiving another diagnosis before Lyme disease. In a separate specialty referral study, 72.2% of patients referred for presumed Lyme disease were classified by the investigators as not having Lyme disease. Neither percentage represents all patients.

What illnesses can be mistaken for Lyme disease?

Symptoms associated with Lyme disease may overlap with fibromyalgia, chronic fatigue syndrome, psychiatric disorders, neurologic illnesses, rheumatologic conditions and other infections. The appropriate differential diagnosis depends on exposure history, examination findings, laboratory results and the pattern of illness.

Can Lyme disease be overdiagnosed?

Yes. Symptoms such as fatigue, joint pain, muscle pain, sleep disturbance and cognitive difficulties are not specific to Lyme disease. Some patients referred for presumed Lyme disease are ultimately considered to have another condition.

Do negative Lyme disease tests contribute to delayed diagnosis?

They can. Antibody tests may be negative early in infection before the immune system has produced detectable antibodies. Test results should be interpreted according to the timing of illness and the overall clinical presentation.

Does delayed diagnosis lead to worse outcomes?

Delayed diagnosis may postpone appropriate treatment and has been associated with prolonged illness or poorer outcomes in some observational reports. However, these studies cannot establish that treatment delay alone explains every persistent symptom.

Clinical Takeaway

The available research does not establish one population-wide rate of Lyme disease misdiagnosis.

Patient surveys document delayed diagnosis, multiple consultations and prior diagnoses. Specialty referral studies also identify patients whose symptoms were considered incorrectly attributed to Lyme disease.

These findings are not contradictory. They represent different patient populations and different forms of diagnostic error.

The central challenge is to recognize Lyme disease when the clinical evidence supports it while continuing to evaluate reasonable alternative explanations for a patient’s symptoms.

Related Articles

Learn more about why Lyme disease is missed, the consequences of delayed recognition and the limitations of diagnostic testing:

Why Lyme Disease Gets Missed, Misdiagnosed, or Dismissed
Six Reasons for Delayed Treatment of Lyme Disease
Impact of Lyme Disease on Working and Caregiving
Persistent Lyme Disease Overview

References

1. Johnson L, Shapiro M, Mankoff J. Removing the mask of average treatment effects in chronic Lyme disease research using big data and subgroup analysis. Healthcare (Basel). 2018;6(4):124.
2. Kobayashi T, Higgins Y, Samuels R, et al. Misdiagnosis of Lyme disease with unnecessary antimicrobial treatment characterizes patients referred to an academic infectious diseases clinic. Open Forum Infect Dis. 2019;6(7):ofz299.
3. Fagen JL, Shelton JA, Luché-Thayer J. Medical gaslighting and Lyme disease: The patient experience. Healthcare (Basel). 2024;12(1):78.
4. Cameron DJ. Consequences of treatment delay in Lyme disease. J Eval Clin Pract. 2007;13(3):470-472.
5. Cameron DJ. Proof that chronic Lyme disease exists. Interdiscip Perspect Infect Dis. 2010;2010:876450.

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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