Lyme or Long COVID? How to Tell the Difference
Three years after recovering from Lyme disease, Jennifer developed COVID-19. Months later, the same crushing fatigue, brain fog, and joint pain returned.
Was it Long COVID — or Lyme again?
This scenario is becoming increasingly common. Lyme disease and Long COVID can look remarkably similar, creating confusion for both patients and clinicians.
For a broader overview of neurologic and cognitive symptoms, see brain fog in Lyme disease.
Why Lyme Disease and Long COVID Feel So Similar
Lyme disease and Long COVID share many overlapping symptoms, making diagnosis difficult in some patients.
Both conditions can cause:
- Brain fog that won’t lift — Difficulty concentrating, losing words mid-sentence, or struggling with familiar tasks
- Exhaustion that sleep doesn’t fix — Severe fatigue despite prolonged rest
- Heart symptoms — Racing heartbeat, skipped beats, or pounding unexpectedly
- Migrating pain — Joint and muscle pain that moves from place to place
- Post-exertional crashes — Physical or mental activity triggering prolonged worsening of symptoms
This overlap is one reason many patients are initially misdiagnosed.
Why the Symptoms Overlap
Although Lyme disease is caused by a bacterial infection and Long COVID follows a viral illness, both conditions appear to involve similar biological pathways.
Researchers have proposed several overlapping mechanisms:
- Post-infectious immune activation — Persistent immune signaling may continue long after the initial infection
- Immune dysregulation — The immune system may remain overactive or fail to return to normal balance
- Neurologic involvement — Both conditions can affect the brain and nervous system, contributing to cognitive dysfunction and sensory symptoms
- Mitochondrial dysfunction — Cellular energy production may be impaired, worsening fatigue and exercise intolerance
- Autonomic nervous system disruption — Dysautonomia may contribute to dizziness, heart rate instability, temperature sensitivity, and exercise intolerance
Learn more about autonomic dysfunction in Lyme disease.
The key distinction: Lyme disease may involve persistent bacterial infection that can respond to antibiotics, while Long COVID is generally viewed as a post-viral inflammatory or immune-mediated condition.
How Treatment Response Can Provide Clues
Treatment response sometimes helps distinguish between Lyme disease and Long COVID.
Patients with Lyme disease may:
- Improve with antibiotics when active infection is present
- Respond to treatment for co-infections such as Babesia
- Benefit from anti-inflammatory and autonomic support strategies
Patients with Long COVID may:
- Require pacing to avoid post-exertional crashes
- Benefit from pulmonary, cardiac, or cognitive rehabilitation
- Respond to therapies targeting inflammation or nervous system regulation
Recovery patterns are rarely straightforward, and symptoms often fluctuate over time.
When Patients Have Both Lyme Disease and Long COVID
Some patients with a prior history of Lyme disease develop new or worsening symptoms after COVID infection.
Others report that symptoms previously attributed to Lyme disease return after COVID illness.
This raises important clinical questions:
- Is Long COVID driving symptoms?
- Has Lyme disease reactivated?
- Are both conditions contributing simultaneously?
These overlapping patterns complicate diagnosis and treatment decisions.
Related overlap syndromes are also discussed in POTS similarities in Long COVID and Lyme disease.
Managing Overlapping Symptoms
In many cases, treatment focuses less on labels and more on shared mechanisms contributing to symptoms.
Management strategies may include:
- Reducing inflammation
- Supporting cellular energy production
- Addressing autonomic dysfunction
- Improving cognitive function and mental clarity
- Carefully pacing activity to avoid symptom crashes
Many patients improve when treatment targets the underlying physiologic dysfunction rather than focusing exclusively on diagnosis labels.
Frequently Asked Questions
Can Lyme disease and Long COVID cause the same symptoms?
Yes. Both conditions can cause brain fog, fatigue, pain, autonomic dysfunction, sleep problems, and exercise intolerance.
Can someone have both Lyme disease and Long COVID?
Yes. Some patients with a history of Lyme disease later develop Long COVID, and symptoms may overlap or worsen.
Can COVID reactivate Lyme disease?
Some clinicians and patients suspect that immune changes following COVID infection may contribute to recurrence or worsening of Lyme-related symptoms, though research remains ongoing.
How do doctors tell the difference between Lyme disease and Long COVID?
Clinical history, tick exposure, testing, symptom timing, and treatment response often provide the most useful clues.
Why do both conditions cause fatigue and brain fog?
Both appear to involve immune dysregulation, neuroinflammation, autonomic dysfunction, and impaired cellular energy production.
Clinical Takeaway
Lyme disease and Long COVID can produce strikingly similar symptoms, including fatigue, cognitive dysfunction, autonomic symptoms, and post-exertional worsening.
In some patients, both conditions may coexist, complicating diagnosis and treatment.
Because symptom patterns overlap so extensively, clinical history, timing, associated findings, and treatment response often provide more insight than any single test result.
Recognizing the overlap between Lyme disease and Long COVID is important because patients may require individualized strategies that address infection, inflammation, autonomic dysfunction, and recovery capacity simultaneously.
Related Articles
Is It Long COVID or Lyme Disease?
Lyme Disease Misdiagnosis
Lyme Disease Symptoms Guide
Neurologic Lyme Disease
Post-Treatment Lyme Disease Syndrome
References
- Stricker RB, Fesler MC. Consequences of Contracting COVID-19 or Taking the COVID-19 Vaccine for Individuals with a History of Lyme Disease. Antibiotics (Basel). 2023;12(4):675.
- Maes M, Morris G, Anderson G. Long COVID diagnostic with differentiation from chronic Lyme disease using machine learning and cytokine hubs. Diagnostics (Basel). 2024;14(15):1641.
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
I was previously treated for a co-infection of Babesia Ducani and Bergerdorfer. Unfortunately, I wasn’t treated for over a decade after chasing down symptoms and misdiagnosis. Even though my initial infection included three bullseye rashes, 105 fever for 10 days, I could barely walk, and had insane headaches, and pain. I was told it was just a virus.
I never truly recovered and spent the next 10+ years in poor health and eventually developed Hashimoto’s, then thyroid cancer, my gallbladder shriveled up and I developed Lipodema.
I had a 4 years period where Lyme went into remission and I felt amazing and back to myself. I have never been able to figure out what changed other than the removed my gallbladder. Unfortunately, the symptoms returned during a period of stress.
Now, I have been diagnosed with Long-Covid and the 200 symptoms and conditions that come with including a re-activation of Epstein-Barr. They have run Lyme tests and did a spinal tape amd nothing came back positive, but I fear they still haven’t ordered the proper tests. When I was originally diagnosed it was after an antibiotic challenge test and they found dead spiroquettes in my blood. I want to do that test again but I can’t remember (imagine that) where It was performed. Do you know how I can get that test? Two of my doctors want me to get an IVIG so we are working with insurance to get it. What do you think about that?
I wish the tests were more reliable. For example, only 2 of 27 patients with chronic neurologic Lyme had a positive test by spinal