Long COVID or Lyme Disease? How to Tell the Difference

Long COVID and Lyme disease can look alike
Fatigue, brain fog, pain, and sweats may overlap
A careful history can change the diagnosis

Long COVID or Lyme disease? He wasn’t losing his mind—he was losing time. Each week blurred into the next as fatigue and fog deepened. When he finally came to my office, he had already accepted a diagnosis that was not quite right.

A patient came to me months after recovering from COVID-19. He still felt drained—exhausted, foggy, and plagued by a burning sensation in his head. He told me, “I’ve accepted that I’m one of those long COVID cases.”

But as I listened and examined his history more closely, several details did not fit. The question of long COVID or Lyme disease became increasingly relevant—the fatigue had actually started before his COVID infection. He also described joint pain, tingling in his hands, and night sweats—symptoms far more suggestive of a tick-borne illness than a viral aftermath.

Recognizing lingering Lyme disease symptoms vs. long COVID

Post-infectious syndromes like long COVID and post-treatment Lyme disease syndrome (PTLDS) can look nearly identical:

1. Brain fog and slowed processing
2. Persistent fatigue
3. Head pressure or burning
4. Muscle and joint pain
5. Dysautonomia or temperature sensitivity

But similarity does not mean sameness. His pattern of symptoms—especially the night sweats, migratory pain, and sensitivity to light—made me reconsider whether this was truly post-COVID at all.

Further testing revealed evidence of Lyme disease and Babesia co-infection—infections that likely predated COVID and re-emerged during immune disruption.

The turning point

We began a course of targeted antibiotics and anti-malarial therapy. Within weeks, the lingering Lyme disease symptoms began to lift—the head pressure eased, fatigue lessened, and concentration returned. For the first time in months, he felt like himself returning—not the exhausted shadow he had been living as.

He did not have a post-viral syndrome after all. He had an untreated tick-borne infection hiding beneath the surface, unmasked by another illness.

Why long COVID or Lyme disease can be hard to separate

Since 2020, millions have been told that persistent symptoms after COVID are “long COVID.” For many, that may be true. But for some, the label can delay the right diagnosis—especially in regions where tick exposure is common.

Tick-borne infections can imitate or amplify post-viral inflammation. Without a full evaluation, a patient recovering from one infection may be living with another. This is especially important when symptoms include night sweats, migratory joint pain, neurologic complaints, or a history of outdoor exposure.

One survey examining individuals with a history of Lyme disease found that the overall burden of illness was not significantly different after contracting COVID-19 or after COVID-19 vaccination. The authors also reported that approximately one in five participants with a history of Lyme disease described symptoms consistent with long COVID, highlighting the overlap clinicians increasingly encounter.

If you have been diagnosed with long COVID but symptoms started before infection, worsened unexpectedly, or include features like night sweats and migratory joint pain, ask your clinician about tick-borne illness testing and a broader differential diagnosis.

Why symptoms overlap

Both long COVID and Lyme disease can trigger prolonged immune activation, inflammation, neurologic dysfunction, and autonomic dysfunction. Patients may experience fatigue, dizziness, exercise intolerance, brain fog, and sleep disruption regardless of the original trigger.

Shared pathways do not mean the conditions are identical—but they do explain why diagnostic confusion is common. Exploring possible persistent Lyme disease mechanisms may help explain why some symptoms linger or overlap.

Researchers have also explored whether biologic signatures may eventually help distinguish these conditions. A 2024 machine-learning study using cytokine hubs reported high sensitivity and specificity in separating long COVID from chronic Lyme presentations, though additional validation and real-world clinical testing remain necessary before widespread adoption.

Frequently Asked Questions

Can Lyme disease be mistaken for long COVID?

Yes. Lyme disease and long COVID can both involve fatigue, brain fog, pain, headaches, dizziness, and exercise intolerance. The timing of symptoms, tick exposure history, night sweats, migratory pain, and co-infection symptoms can help guide further evaluation.

What symptoms may point more toward Lyme disease than long COVID?

Symptoms that began before COVID infection, migratory joint pain, tingling or burning sensations, night sweats, light sensitivity, and a history of tick exposure may raise suspicion for Lyme disease or co-infections.

Can COVID unmask a tick-borne infection?

In some patients, another infection or immune stressor may make pre-existing symptoms more noticeable. COVID may not be the original cause of every lingering symptom pattern.

Should patients with long COVID symptoms be tested for Lyme disease?

Testing may be appropriate when the clinical history suggests tick-borne illness, especially in endemic regions or when symptoms do not fit the expected post-COVID pattern.

Can Babesia cause symptoms that resemble long COVID?

Yes. Babesia infection may contribute to fatigue, night sweats, dizziness, exercise intolerance, and cognitive symptoms that overlap with long COVID presentations.

Clinical Takeaway

Lingering symptoms deserve investigation, not assumption. When “long COVID” does not behave like COVID—when symptoms predate infection, include atypical features, or fail to improve—clinicians should revisit the differential diagnosis, including Lyme disease and co-infections.

A careful history and appropriate testing can reveal what viral illness may have obscured.

Not all long hauls begin with COVID—sometimes, they begin in the woods.

Related Articles

These articles explore overlapping symptoms, diagnostic confusion, and persistent symptom mechanisms.

Lyme vs. long COVID
Lyme disease misdiagnosed as long COVID
Persistent Lyme disease mechanisms
Long COVID Q&A sponsored by Project Lyme

References

1. Centers for Disease Control and Prevention. Clinical Overview of Long COVID.
2. Cameron DJ, McWhinney SR. Consequences of Contracting COVID-19 or Taking the COVID-19 Vaccine for Individuals with a History of Lyme Disease. Antibiotics (Basel). 2023;12(3):493.
3. Patterson BK, Guevara-Coto J, Mora J, Francisco EB, Yogendra R, Mora-Rodríguez RA, et al. Long COVID diagnostic with differentiation from chronic lyme disease using machine learning and cytokine hubs. Sci Rep. 2024;14(1):19743.

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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