Why Do Some Lyme Disease Patients Feel Worse When Standing?
Symptoms may worsen while standing and improve when reclining
Orthostatic intolerance does not always mean POTS
Heart rate, blood pressure, and competing causes require evaluation
Some patients with Lyme disease feel reasonably well while sitting or lying down but become dizzy, weak, foggy, nauseated, or exhausted after standing.
When Lyme disease symptoms get worse when standing, the problem may involve orthostatic intolerance. This means the body has difficulty adjusting to an upright position.
Orthostatic intolerance can occur as part of autonomic nervous system dysfunction. However, feeling worse while standing does not establish that Lyme disease is the cause, and it does not automatically mean a patient has postural orthostatic tachycardia syndrome, commonly called POTS.
Why Standing Can Trigger Symptoms
When a person stands, gravity shifts blood toward the legs and abdomen. The autonomic nervous system normally responds by tightening blood vessels and making small adjustments in heart rate. These changes help maintain blood flow to the heart and brain.
If that response is delayed or inadequate, standing may produce symptoms even when the person felt relatively comfortable while reclining.
Patients may notice:
- Lightheadedness or dizziness
- Weakness or shakiness
- Palpitations
- Blurred or dimmed vision
- Brain fog
- Nausea
- Head pressure
- Shortness of breath
- Sudden fatigue
- Feeling as though they may faint
The symptoms often improve after sitting or lying down, although recovery may not be immediate.
What Is Orthostatic Intolerance?
Orthostatic intolerance is an umbrella term for symptoms that develop or worsen while upright and improve when reclining.
It is not a single diagnosis. Several conditions can produce this pattern, including dehydration, low blood volume, medication effects, anemia, heart rhythm problems, orthostatic hypotension, POTS, and other forms of autonomic dysfunction.
Heat, prolonged standing, illness, large meals, a hot shower, or physical exertion may make the symptoms more noticeable. These situations can widen blood vessels or redirect blood flow, placing additional demands on circulation.
What Has Been Found in Lyme Disease Patients?
Researchers have begun examining autonomic symptoms in patients with persistent symptoms following treatment for Lyme disease.
In a 2025 study, 37 patients with post-treatment Lyme disease completed a questionnaire measuring symptoms across several autonomic domains. Their overall autonomic symptom burden was higher than that reported by healthy controls. Some symptom patterns were comparable to those seen in patients with POTS.
The researchers also reviewed 10-minute active stand testing from 210 patients. Only 9 patients, or 4.29%, developed the increase in heart rate classified as orthostatic tachycardia.
This finding is important because it suggests that patients may report substantial symptoms while standing without meeting the heart-rate criteria for POTS.
The study does not prove that Lyme disease directly caused the autonomic symptoms. It does, however, support taking upright symptoms seriously and evaluating them rather than relying on symptoms alone to assign a diagnosis.
Does Feeling Worse While Standing Mean POTS?
No. POTS is one cause of orthostatic intolerance, but the terms are not interchangeable.
In adults, POTS generally involves a sustained heart-rate increase of at least 30 beats per minute within 10 minutes of standing, without the blood-pressure decrease required for orthostatic hypotension. A threshold of at least 40 beats per minute is generally used for adolescents.
The diagnosis also requires chronic upright symptoms and evaluation for other explanations for the increased heart rate.
Some Lyme disease patients may meet these criteria. Others may have orthostatic symptoms without the characteristic heart-rate increase. For a more detailed discussion, see POTS and Lyme Disease.
Can Heart Rate and Blood Pressure Be Normal?
Yes. A normal heart rate or blood pressure during a brief office measurement does not necessarily explain what happens after several minutes of standing.
A small retrospective study of 10 patients with post-treatment Lyme disease syndrome found reduced cerebral blood-flow velocity during tilt-table testing in 7 patients. The researchers also reported evidence of small-fiber neuropathy and autonomic dysfunction.
That study was too small to determine how commonly these findings occur. It does raise the possibility that some patients can experience reduced blood flow to the brain while upright even when routine heart-rate and blood-pressure measurements do not fully capture the problem.
This remains an emerging area of research and should not be interpreted as proof that every patient with Lyme disease and dizziness has impaired cerebral blood flow.
What Can Make Upright Symptoms Worse?
Patients often notice that standing becomes more difficult under particular conditions, including:
- Hot weather or hot showers
- Dehydration
- Prolonged standing
- Large meals
- Viral illness or fever
- Travel or disrupted sleep
- Physical overexertion
- Medications that lower blood pressure or increase heart rate
Recognizing these patterns can help a patient describe the problem more clearly during a medical visit.
How Are These Symptoms Evaluated?
Evaluation usually begins with a careful history. The clinician may ask how quickly symptoms appear, how long the patient can remain upright, whether reclining helps, and whether symptoms are affected by meals, heat, exertion, or hydration.
Heart rate and blood pressure may be measured after resting and then repeatedly during as much as 10 minutes of standing. Some patients require formal autonomic or tilt-table testing when symptoms remain unexplained.
Testing may also be needed to look for other causes, such as:
- Anemia
- Dehydration or blood loss
- Thyroid disease
- Medication side effects
- Heart rhythm abnormalities
- Adrenal or metabolic disorders
- Neurologic conditions
New fainting, chest pain, severe shortness of breath, sustained rapid heart rate, or new neurologic symptoms require prompt medical evaluation.
What May Help With Orthostatic Symptoms?
Management depends on the cause and the patient’s other medical conditions. Measures commonly considered for orthostatic intolerance include maintaining appropriate hydration, avoiding prolonged standing, rising gradually, and limiting exposure to excessive heat.
Some patients may benefit from compression garments, carefully supervised recumbent exercise, changes in meal size, or adjustments to medications that aggravate symptoms.
Increasing salt is sometimes recommended for selected patients, but it is not appropriate for everyone. Patients with high blood pressure, heart disease, kidney disease, or other medical concerns should discuss salt and fluid changes with their clinician.
Prescription treatment may be considered when symptoms remain disabling, but it should be based on the patient’s blood pressure, heart-rate pattern, diagnosis, and overall health.
Frequently Asked Questions
Why do my Lyme disease symptoms get worse when I stand?
Standing shifts blood toward the legs and abdomen. If the autonomic nervous system does not adjust circulation effectively, symptoms such as dizziness, weakness, palpitations, brain fog, or fatigue may appear or worsen.
Does feeling worse when standing mean I have POTS?
No. POTS is one form of orthostatic intolerance with defined heart-rate and clinical criteria. A person can have significant upright symptoms without meeting those criteria.
Can orthostatic symptoms occur with a normal blood pressure?
Yes. Some patients experience orthostatic symptoms without a large blood-pressure decrease. Heart-rate responses, symptom timing, medications, hydration, and other aspects of autonomic function may need evaluation.
Why do hot showers make upright symptoms worse?
Heat widens blood vessels and can increase blood pooling in the lower body. This may reduce the amount of blood returning to the heart and make dizziness, weakness, or palpitations more noticeable.
When should symptoms while standing be evaluated urgently?
Fainting, chest pain, severe shortness of breath, a sustained rapid or irregular heartbeat, or new neurologic symptoms should be evaluated promptly.
Clinical Takeaway
Feeling worse when standing may reflect orthostatic intolerance or another problem affecting circulation. The symptom pattern deserves evaluation, particularly when it repeatedly improves after sitting or lying down.
Current research suggests that autonomic symptoms can occur in patients with persistent symptoms following Lyme disease, but the evidence does not establish one mechanism or show that every symptomatic patient has POTS.
Upright symptoms are clinically meaningful even when a brief heart-rate or blood-pressure measurement appears normal.
Related Articles
Autonomic Dysfunction in Lyme Disease
Dizziness and Lyme Disease
Exercise Intolerance in Lyme Disease
This article is intended for educational purposes and does not replace individualized medical evaluation or treatment.
References
- Adler BL, et al. Autonomic symptoms in post-treatment Lyme disease: Insights from the COMPASS-31 and the 10-minute active stand test. Mayo Clin Proc Innov Qual Outcomes. 2025;9(6):100674.
- Novak P, Felsenstein D, Mao C, Octavien NR, Zubcevik N. Association of small fiber neuropathy and post treatment Lyme disease syndrome. PLoS One. 2019;14(2):e0212222.
- Adler BL, et al. Dysautonomia following Lyme disease: A key component of post-treatment Lyme disease syndrome? Front Neurol. 2024;15:1344862.
- Bryarly M, Phillips LT, Fu Q, Vernino S, Levine BD. Postural orthostatic tachycardia syndrome: JACC focus seminar. J Am Coll Cardiol. 2019;73(10):1207-1228.
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
