Postural Orthostatic Tachycardia Syndrome (POTS): An Overlooked Autonomic Disorder

By Dr Hazel Batten, Integrative GP at Remede Wellness Medicine

Introduction

Postural Orthostatic Tachycardia Syndrome (POTS) is a chronic disorder of the autonomic nervous system marked by orthostatic intolerance, where standing triggers a sustained increase in heart rate of more than 30 beats per minute in adults (or over 40 in adolescents) without a corresponding drop in blood pressure. Affecting an estimated 0.1–1% of the population—most commonly young women—POTS remains under-diagnosed and is frequently misinterpreted as anxiety or physical de-conditioning, leading to delays in appropriate recognition and care.

Pathophysiology

The pathophysiology of Postural Orthostatic Tachycardia Syndrome is complex and multifactorial. Contributing mechanisms may include hypovolemia, or reduced circulating blood volume; a hyper-adrenergic state characterised by excessive sympathetic nervous system activity; and neuropathic changes that impair peripheral vasoconstriction, resulting in blood pooling in the lower extremities. Emerging evidence also suggests potential links with autoimmune processes and post-viral syndromes, particularly in the aftermath of COVID-19.

Clinical Presentation

The hallmark feature of Postural Orthostatic Tachycardia Syndrome is a rapid increase in heart rate upon standing. Alongside this, individuals often experience lightheadedness, palpitations, and chest discomfort, as well as more systemic symptoms such as fatigue, exercise intolerance, cognitive difficulties commonly described as “brain fog,” gastrointestinal disturbances, headaches, and sleep problems. Symptoms are typically aggravated by factors such as heat exposure, dehydration, prolonged standing, and, in women, the menstrual cycle.

Diagnosis

Diagnosis of Postural Orthostatic Tachycardia Syndrome is typically based on orthostatic vital sign assessment or tilt-table testing, demonstrating a sustained rise in heart rate of at least 30 beats per minute in adults (or 40 in adolescents) within 10 minutes of standing, in the absence of orthostatic hypotension. It is important to exclude other potential causes that can mimic POTS, such as anaemia, thyroid disorders, dehydration, or structural heart disease. Additional investigations may include routine blood tests, specialised autonomic function testing, and, in some cases, measurement of catecholamine levels.

Management

Management of Postural Orthostatic Tachycardia Syndrome typically begins with non-pharmacological strategies, which form the cornerstone of care. These include:

• Increasing daily fluid intake to 2–3 litres and salt consumption up to 10 grams if tolerated
• Using compression garments to reduce blood pooling
• Engaging in physical reconditioning through recumbent exercise and gradual standing training.
• Patients are also advised to avoid common symptom triggers such as heat, large meals, and alcohol.

When lifestyle measures alone are insufficient, pharmacological options may be considered and are often tailored through trial and error. Commonly used medications include:

• Fludrocortisone to expand blood volume
• Midodrine to promote vasoconstriction
• Agents such as Beta-blockers or Ivabradine to help control heart rate.
• In selected cases, pyridostigmine or serotonin-modulating drugs (SSRIs/SNRIs) may also provide benefit.

Prognosis

The prognosis of Postural Orthostatic Tachycardia Syndrome is highly variable. While some individuals experience improvement with lifestyle modifications and appropriate treatment, others continue to face persistent and often debilitating symptoms. The condition can significantly reduce quality of life, impacting daily activities, employment, and schooling. Long-term outcomes remain incompletely understood, and further research is particularly needed to clarify prognosis in patients who develop POTS after COVID-19.

Conclusion

Postural Orthostatic Tachycardia Syndrome is a disabling yet frequently under-recognised condition. Early diagnosis and tailored management strategies can make a meaningful difference in improving quality of life for those affected. Greater awareness among healthcare providers is essential, especially in light of the increasing number of post-viral dysautonomia cases seen in recent years.