Estimates of POTS prevalence vary from 0.1-1% of the general population. It is more common in women (80-85%), typically between 15-50 years of age. Up to 30% of long COVID patients may experience POTS. Many patients are probably misdiagnosed with other conditions before receiving a correct POTS diagnosis, obscuring the true incidence of the disease.

The exact cause of POTS is not fully understood, but it is clear that it is not a single disease. Instead, it is a heterogeneous syndrome with multiple underlying pathophysiological mechanisms that can vary from person to person. Among the different types and contributing factors are:

• Neuropathic POTS where small-fiber autonomic nerve deterioration causes impaired constriction of blood vessels leading to blood pooling in the lower limbs.

• Hyperadrenergic POTS from excessive ANS sympathetic nerve activity and elevated norepinephrine, the body’s “fight or flight” hormone.

• Hypovolemic POTS from reduced blood volume.

• Associations with autoimmune disorders where the body’s immune system may attack its own tissues.

• Co-morbid conditions such as a family history of dysautonomia, connective tissue disorders like Hypermobile Ehlers-Danlos syndrome or immune system disorders like Mast Cell Activation Syndrome (MCAS).

• Viral infections such as long COVID-19. 

In many cases, POTS develops suddenly after a significant physiological stressor, such as a viral infection, major surgery, pregnancy, or physical trauma. This suggests that these events may act as a trigger in a genetically susceptible individual.

POTS is characterized by a wide array of symptoms that can range from mild to profoundly disabling. While its core definition is rooted in a cardiovascular response to a body position change, the condition's manifestation extends far beyond the heart. Symptoms can be broadly categorized into those that are strictly orthostatic (occurring upon standing) and those that are systemic (occurring regardless of posture).

Orthostatic symptoms:

• Cardiovascular:  Heart palpitations;  fast heartbeat on standing (30+ bpm increase in adults; 40+ in adolescents.

• Dizziness or Lightheadedness:  Caused by reduced blood flow to the brain upon standing.

• Fainting or Pre-syncope:  Episodes of fainting (syncope) or the sensation of nearly fainting, which can occur after standing for a prolonged period.

• Chest Pain and Shortness of Breath: These symptoms can be exacerbated when upright.

• Shakiness and Sweating: Often result from the body's heightened sympathetic nervous system activity as it attempts to compensate for blood pooling.

• Weakness: A feeling of heaviness or weakness in the legs and arms, especially when standing still.

Systemic or non-orthostatic symptoms:

• Cognitive Dysfunction:  Brain fog or difficulty concentrating, potentially affecting a person’s ability to engage in work or educational activities.

• Neurological:  Headaches, migraines, blurred vision or tremors.

• Fatigue:  Extreme tiredness even after minimal physical exertion.

• Gastrointestinal:  May include nausea, vomiting, bloating, diarrhea, constipation or abdominal pain.

• Other:  Insomnia, cold or painful extremities, purple discoloration of the hands and feet from blood pooling.

A number of factors can exacerbate POTS symptoms and lead to flare-ups, including heat exposure, dehydration, prolonged standing, large meals, alcohol consumption, infections, menstruation and stress.

Diagnosing POTS can be challenging due to its varied symptoms and significant overlap with other conditions. The process typically involves a combination of clinical evaluation and objective physiological testing including:

• Review of a patient’s medical history, symptoms and possible triggers.

• Standing or tilt table test:  Measure blood pressure and a heart-rate increase of ≥30 bpm (≥40 bpm in adolescents) within 10 minutes of standing or tilt;  the key observation is a sustained heart rate increase in absence of a significant blood pressure drop.

• Blood tests to rule out thyroid disease, anemia or adrenal insufficiency.

• Autonomic function tests such as the Valsalva maneuver to assess the heart’s response to nerve stimulation and the Quantitative Sudomotor Axon Reflex Test (QSART) to measure sweat production.

• An electrocardiogram (ECG) can be performed to rule out other heart rhythm abnormalities.

There is no cure for POTS, but symptoms often can be managed with a combination of lifestyle interventions, physical therapy and medications. Lifestyle modifications may include increased fluid and salt intake, compression stockings, a gradual physical reconditioning exercise program, and avoidance of prolonged standing, heat exposure and large meals. Medications may include fludrocortisone to expand plasma volume, midodrine to increase vasoconstriction, beta-blockers or ivabradine to reduce heart rate, pyridostigmine to treat autonomic neuropathy by increasing neurotransmitter levels, clonidine for hyperadrenergic POTS and antihistamines for MACS. Management is highly individualized, based on subtype and often multidisciplinary.

POTS is a chronic condition with a variable course. Some patients experience significant improvement over time, while others have persistent symptoms requiring ongoing care. Life expectancy is generally normal. Early diagnosis and management can greatly improve the quality of life.

1. Raj SR. 2013. “Postural tachycardia syndrome (POTS).” Circulation 127(23): 2336-42. doi: 10.1161/CIRCULATIONAHA.112.144501. PMID: 23753844; PMCID: PMC3756553.

2. Benarroch EE. 2012. “Postural tachycardia syndrome: a heterogeneous and multifactorial disorder.” Mayo Clin Proc. 87(12):1214-25. doi: 10.1016/j.mayocp.2012.08.013. Epub 2012 Nov 1. PMID: 23122672; PMCID: PMC3547546.

3. Dysautonomia International:  Postural Orthostatic Tachycardia Syndrome.

4. National Institute of Neurological Disorders and Stroke:  Postural Orthostatic Tachycardia Syndrome.

5. Australian POTS Foundation:  Living with POTS.