When Was Postural Orthostatic Tachycardia Syndrome Discovered?

Postural orthostatic tachycardia syndrome, known as POTS, was formally named and described in a 1993 paper published in the journal Neurology by researchers Ronald Schondorf and Phillip Low at the Mayo Clinic. That paper coined the term and established POTS as a distinct clinical entity, but the symptoms it describes had been recognized under different names for well over a century. The gap between those early observations and the 1993 naming helps explain why POTS remained so poorly understood for so long, and why many patients still struggle to get a diagnosis today.

The 1993 Paper That Named POTS

Schondorf and Low’s landmark study reviewed records of patients between the ages of 20 and 51 who visited the Mayo Autonomic Reflex Laboratory and showed an abnormal heart rate increase either at rest or during a head-up tilt test.¹ The paper proposed that POTS was a milder form of a known condition called acute pandysautonomia, in which the autonomic nervous system suddenly fails to regulate basic body functions. By giving the syndrome its own name and framing it as a distinct disorder rather than a vague collection of symptoms, the researchers created a clinical category that doctors could diagnose, study, and eventually treat. Before 1993, patients with the same set of symptoms had no unifying label, which made research nearly impossible and left most of them undiagnosed or misdiagnosed.

Symptoms Before They Had a Name

The experience of feeling faint, dizzy, and overwhelmed by a racing heart upon standing is hardly a modern complaint. During the American Civil War, physician Jacob Mendes Da Costa described a cluster of symptoms in soldiers that included palpitations, chest pain, and exercise intolerance. He called it “irritable heart” or “soldier’s heart.” By World War I, the same constellation had been relabeled “effort syndrome” and “neurocirculatory asthenia.” In each case, the patients shared a core experience: standing or exertion sent their heart rate surging, they felt lightheaded, and no structural heart disease could be found.

These earlier labels carried a stigma. “Effort syndrome” implied the soldier simply could not handle the physical demands of service, and “neurocirculatory asthenia” suggested a constitutional weakness. The conditions were often dismissed as psychological. This framing persisted for decades, and it cast a long shadow. Even after POTS was formally defined in 1993, the legacy of treating these symptoms as imagined or exaggerated continued to shape how many clinicians responded to patients who described them.

Why It Took Until 1993

Autonomic testing technology was a prerequisite. Tilt-table testing, which tips a patient from lying flat to a near-standing angle while monitoring heart rate and blood pressure beat by beat, became widely available in research settings only in the 1980s. Before that, there was no reliable, standardized way to measure what was happening to a patient’s cardiovascular system during the transition from lying down to standing up. Without objective measurements, clinicians were left with patient-reported symptoms, which are easy to attribute to anxiety or deconditioning.

The Mayo Clinic’s Autonomic Reflex Laboratory, where Schondorf and Low worked, was one of the few centers equipped to perform detailed autonomic testing. Their ability to document the precise heart rate changes during controlled tilt tests is what made it possible to define POTS as a measurable, reproducible phenomenon rather than a subjective complaint. The technology created the diagnosis.

How Diagnostic Criteria Evolved After 1993

The original 1993 description established the basic idea, but it took years for the medical community to agree on exactly where to draw the line between a normal heart rate response to standing and a pathological one. Current consensus criteria define POTS by a sustained heart rate increase of at least 30 beats per minute within ten minutes of standing or head-up tilt, without a significant drop in blood pressure. For adolescents aged 12 to 19, the threshold is higher: at least 40 beats per minute.² The absence of a large blood pressure drop is what distinguishes POTS from orthostatic hypotension, a different condition in which blood pressure plummets when you stand.

These criteria have not been static. Different research groups and guidelines have used varying heart rate thresholds, different tilt angles, and different test durations over the years.³ The pediatric criteria are a good example of how the numbers shifted. Research showed that a heart rate jump of 30 beats per minute is actually within the normal range for children and adolescents, meaning the adult cutoff would massively over-diagnose healthy kids. One study of high-school students found heart rate changes as high as 48 beats per minute during normal standing.⁴ That finding pushed researchers to recommend the higher 40-beat threshold for younger patients and to add absolute heart rate ceilings as well.

The Testing Itself Is Still Being Refined

Even with agreed-upon thresholds, the method of testing matters more than many clinicians realize. A head-up tilt test, where a motorized table tilts you passively, produces a somewhat different heart rate response than an active standing test, where you simply stand up from a lying position. A study comparing the two in 60 POTS patients found that the tilt table identified the condition in 98 percent of participants, while the active standing test caught only 74 percent. The gap narrowed when the heart rate threshold for the standing test was lowered to 27 beats per minute, but the tilt table still outperformed it.⁵ This discrepancy matters because many clinics use the simpler standing test rather than a tilt table, and some patients may receive a false negative as a result.

Why POTS Gets Mistaken for Anxiety

One of the most persistent problems in the history of POTS, stretching from the “soldier’s heart” era all the way to the present, is misdiagnosis as an anxiety disorder. The overlap in symptoms is real: a racing heart, shortness of breath, trembling, and a feeling of dread are features of both panic attacks and POTS episodes. But the mechanism is different. In POTS, the autonomic nervous system is misbehaving in a measurable, physiological way. The anxiety-like symptoms are a downstream consequence of that malfunction, not the cause of it.

Case reports and reviews have documented that POTS can go undiagnosed for years, with patients cycling through psychiatric evaluations and anti-anxiety medications that do nothing to address the underlying problem.⁶ The dismissal is especially damaging because it delays effective treatment and reinforces the old “effort syndrome” stigma that the patient’s symptoms are not physically real.

What Triggers POTS

POTS often appears after a clear triggering event rather than developing gradually. Viral infection is the most commonly reported trigger, with studies estimating that roughly 28 to 41 percent of patients trace the onset of their symptoms to a preceding illness. Other documented triggers include surgery, pregnancy, and traumatic injury.⁷ Epstein-Barr virus, various upper respiratory infections, and gastrointestinal infections have all been implicated.

The COVID-19 pandemic brought an enormous surge in new POTS cases and, with it, a wave of public awareness. Case series documented patients developing POTS after even mild COVID-19 infections, sometimes in people who were previously healthy and athletic.⁸ The post-COVID wave did something the POTS community had been trying to achieve for decades: it forced the condition into mainstream medical conversation. Researchers who had never studied autonomic disorders were suddenly confronting them in their long COVID clinics, and the number of publications on POTS increased sharply.

The Blood Volume Problem

Not everyone with POTS has the same underlying physiology, which is one reason the condition took so long to pin down. One well-studied subtype involves low blood volume. Research comparing POTS patients to healthy controls found that patients had a substantial deficit in plasma volume and red blood cell volume, adding up to a total blood volume deficit of nearly 700 milliliters compared to controls. What made this finding especially puzzling was that the hormonal system that should compensate for low blood volume was not responding properly. Plasma renin activity was identical between the two groups, and aldosterone, the hormone that tells the kidneys to retain salt and water, was paradoxically lower in the POTS patients.⁹

This “renin-aldosterone paradox” explains why simple advice like “drink more water” is not always enough. If the hormonal system that retains fluid is not working correctly, the body may just excrete extra fluid rather than using it to rebuild blood volume. It also helps explain why salt loading, which raises fluid retention through a different pathway, is a cornerstone of POTS management.

The Autoimmune Theory

One of the most significant developments since the original 1993 discovery has been the growing evidence that POTS may be an autoimmune condition in at least some patients. Researchers have identified autoantibodies, immune proteins that attack the body’s own receptors, targeting several types of receptors in the cardiovascular and nervous systems of POTS patients.

One study found that half of the POTS patients tested had elevated autoantibodies against a receptor called the M2 muscarinic acetylcholine receptor, which plays a role in heart rate regulation. None of the healthy controls showed the same elevation. The antibodies appeared to interfere with the receptor’s normal function, potentially exaggerating the heart rate increase that occurs when standing.¹⁰ A larger study detected elevated autoantibodies against the adrenergic alpha-1 receptor in 89 percent of POTS patients and against the muscarinic M4 receptor in 53 percent, supporting the idea that POTS may be autoimmune in the majority of cases rather than just a small subset.¹¹

Further research linked specific muscarinic receptor autoantibodies to gastrointestinal symptoms and overall disease severity in POTS patients, suggesting these antibodies are not just bystanders but active contributors to how sick a person feels.¹² If the autoimmune hypothesis holds up, it would open the door to treatments that target the immune system directly rather than just managing symptoms.

The Overlap With Hypermobility and Mast Cell Disorders

Clinicians who treat POTS have long noticed that their patients frequently have other conditions as well, particularly joint hypermobility and mast cell activation syndrome. This triad, sometimes called the “trifecta” in patient communities, has now been documented in the research literature. Reports describe a significant association between hypermobility spectrum disorders (including hypermobile Ehlers-Danlos syndrome), POTS, and mast cell activation syndrome, with all three contributing to disabling gastrointestinal symptoms among other problems.¹³

The reason these conditions cluster together is still being worked out. One theory is that loose connective tissue in hypermobile patients allows blood vessels to stretch excessively, pooling blood in the lower body and triggering the compensatory tachycardia that defines POTS. The mast cell connection may relate to immune dysregulation that overlaps with the autoantibody findings described above. For patients, the practical takeaway is that if you have one of these conditions, it may be worth being evaluated for the others.

Treatment Without an Approved Drug

Despite being named over 30 years ago, POTS still has no pharmacological therapy approved by any major regulatory agency.¹⁴ Every medication used to treat POTS is prescribed off-label, meaning it was approved for a different condition and is being repurposed based on clinical experience and small trials. This situation reflects both the relative neglect of autonomic disorders in drug development and the heterogeneity of POTS itself: a drug that helps one subtype may do nothing for another.

The treatment approach that has the strongest evidence behind it is structured exercise training combined with increased salt and fluid intake. A trial comparing exercise training to the beta-blocker propranolol found that three months of exercise was superior at normalizing heart rate responses to standing and improving quality of life.¹⁵ The catch is that exercise can feel terrible for POTS patients at first, because upright activity is exactly what triggers their symptoms. The recommended workaround is to start with horizontal exercises like rowing, swimming, or recumbent cycling, which allow training without the postural stress that provokes symptoms.¹⁶ Patients gradually transition to upright exercise over weeks or months as their conditioning improves.

Lessons From Space Medicine

An unexpected thread in POTS research runs through NASA. Astronauts returning from space frequently develop orthostatic intolerance, a condition that looks very similar to POTS: their heart rate spikes on standing, they feel dizzy and fatigued, and their blood volume is reduced. The cause in astronauts is straightforward: microgravity causes cardiovascular deconditioning because the heart and blood vessels no longer need to fight gravity to circulate blood. When the astronaut returns to Earth, the system is temporarily unable to cope with upright posture.

Research into countermeasures for astronauts, including exercise protocols, fluid loading strategies, and compression garments, has fed directly into POTS treatment approaches. The connection also runs in the other direction: studying POTS patients on Earth may help researchers understand and prevent the autonomic dysfunction that threatens long-duration space missions.¹⁷ The parallel is not perfect, since astronauts typically recover within weeks while POTS patients may be symptomatic for years, but the shared physiology has made each field useful to the other in ways that neither anticipated when POTS was first described in that 1993 paper at the Mayo Clinic.