Postural Orthostatic Tachycardia Syndrome is a form of dysautonomia, which is a disorder of the autonomic nervous system (ANS). The ANS is the “automatic” part of your nervous system that controls all the functions you do not consciously think about, such as your heart rate, blood pressure, digestion, and body temperature regulation.

The core problem in POTS involves the body’s response to gravity.

• When a healthy person stands up, gravity pulls about half a liter of blood down into their legs and abdomen. The ANS instantly senses this and signals the blood vessels in the lower body to constrict or tighten. This action pushes blood back uphill to the heart and brain, keeping blood pressure stable with only a small, brief increase in heart rate.
• In a person with POTS, this automatic “pipe-squeezing” mechanism is faulty. When they stand up, their blood vessels do not constrict properly, and blood pools in their lower body. The brain senses a critical drop in blood return and, in a panic, it desperately tells the heart to beat much faster to try to compensate and maintain blood pressure.

This excessive and sustained increase in heart rate upon standing, without a major drop in blood pressure, is the defining feature of POTS. The racing heart is not the primary problem; it is the body’s inefficient and symptomatic solution to the underlying failure of the autonomic nervous system to manage the simple stress of being upright.

In my experience, patients often go years undiagnosed. Despite experiencing daily symptoms like dizziness and heart palpitations, POTS is commonly misunderstood or misattributed to anxiety.

The exact cause of POTS is often unknown. It is considered a syndrome, a collection of symptoms that is likely the final common pathway for several different underlying mechanisms. It is not a single disease.

Researchers have identified several potential subtypes and contributing factors:

• Neuropathic POTS: This may be the most common form, where there is damage to the small fiber nerves (small-fiber neuropathy) that are responsible for signaling the blood vessels in the legs and abdomen to constrict.
• Hyperadrenergic POTS: This form is characterized by an over-response of the “fight-or-flight” nervous system, leading to excessively high levels of the stress hormone norepinephrine upon standing.
• Hypovolemic POTS: In this form, the individual has an abnormally low volume of blood circulating in their system, which exacerbates the effects of blood pooling.
• Autoimmune POTS: There is growing evidence that, in some individuals, POTS may be an autoimmune disorder, where the body produces autoantibodies that attack key receptors in the autonomic nervous system.

Clinically, I’ve seen a range of triggers including viral infections, trauma, surgery, or autoimmune issues contribute to POTS. Some cases have a genetic or idiopathic basis.

A person develops POTS when their autonomic nervous system becomes dysfunctional. This is not a contagious condition. The onset is often sudden and can frequently be traced back to a specific triggering event.

Common triggers for the development of POTS include:

• A Viral or Bacterial Infection: Many patients report that their POTS symptoms began immediately following an illness like mononucleosis (caused by the Epstein-Barr virus), influenza, or more recently, COVID-19. POTS is now recognized as a common component of “Long COVID.”
• Pregnancy and Childbirth: The significant physiological and hormonal shifts of pregnancy can trigger the onset of POTS.
• Major Surgery, Trauma, or a Significant Medical Event.

Associated Conditions and Demographics

• Risk Factors: The most significant risk factors are being female and being between the ages of 15 and 50. It is estimated that 1 in 100 teenagers develop POTS (Dysautonomia International, n.d.).
• Comorbidities: POTS is very commonly seen alongside two other conditions, sometimes referred to as the “trifecta”:
  • Hypermobile Ehlers-Danlos Syndrome (hEDS), a genetic connective tissue disorder.
  • Mast Cell Activation Syndrome (MCAS), an immune disorder.

Patients often ask why this “suddenly started”, I explain that in many cases, it begins after a physical stressor that may have unmasked underlying autonomic dysfunction.

The hallmark of POTS is experiencing symptoms of orthostatic intolerance (difficulty with being upright) that are relieved by lying down, accompanied by a rapid heart rate upon standing. The symptoms are chronic, multi-systemic, and can be debilitating.

The most common signs and symptoms include:

• Orthostatic Symptoms:
  • Dizziness and lightheadedness upon standing.
  • Near-fainting (pre-syncope) or, in some cases, fainting (syncope).
  • Heart palpitations, a feeling of a racing or pounding heart.
• Neurological Symptoms:
  • “Brain fog,” which is a profound difficulty with concentration, memory, and thinking clearly.
  • Headaches and migraines.
  • Blurred or tunneled vision upon standing.
• Constitutional Symptoms:
  • Profound fatigue that is not relieved by sleep and is often described as “bone-crushing.”
  • Exercise intolerance, where even minor physical activity can worsen symptoms.
• Gastrointestinal Symptoms: Nausea, bloating, abdominal pain, diarrhea, and constipation are very common.
• Other Symptoms: Temperature dysregulation (feeling hot or cold), tremors, poor sleep, and a purplish discoloration of the legs upon standing (blood pooling).

Patients describe lightheadedness, rapid heartbeat, fatigue, brain fog, shakiness, and sometimes nausea or chest discomfort usually when standing or after prolonged sitting.

The journey to a POTS diagnosis is notoriously long and frustrating for many patients. Because the symptoms are so varied and a routine physical exam is often normal, patients are frequently misdiagnosed with chronic anxiety or panic disorder for years.

The diagnosis is made by a specialist, such as a cardiologist or neurologist, based on a specific set of criteria and confirmed with a positional test.

Diagnostic Criteria: To be diagnosed with POTS, a person must meet the following criteria:

1. A sustained increase in heart rate of at least 30 beats per minute (or 40 bpm for adolescents) within 10 minutes of moving from a reclining to a standing position.
2. This must occur in the absence of orthostatic hypotension (a significant drop in blood pressure of more than 20/10 mmHg).
3. The patient must have chronic symptoms of orthostatic intolerance for at least three months.

Diagnostic Tests

• In-Office 10-Minute Stand Test: This is the simplest way to test for POTS. Heart rate and blood pressure are measured while the patient is lying down, and then at 2, 5, and 10-minute intervals after they stand up. The sustained heart rate increase is documented.
• Formal Tilt Table Test: This is considered the gold standard for diagnosis. The patient lies on a table that is slowly tilted upright to a 70-degree angle. Their heart rate and blood pressure are continuously monitored to see how their body responds to the change in posture without the influence of muscle contraction.
• Ruling Out Other Causes: A doctor will also perform a thorough workup to rule out other conditions that could cause a rapid heart rate. This includes an ECG, an echocardiogram to check the heart’s structure, and blood tests to check for anemia and thyroid problems.

Clinically, I always evaluate symptom patterns over time and use a standing test or tilt table test to observe heart rate changes and confirm the diagnosis.

There is no cure for POTS, but it is a manageable condition. Treatment is a long-term, multi-pronged approach that is highly individualized. The goal is to manage the symptoms, increase functional capacity, and improve quality of life.

1. Non-Pharmacological Management (The Cornerstone of Treatment)

For most patients, lifestyle and physical management strategies are the most important and effective treatments.

• Increased Fluid and Salt Intake: This is the number one intervention. Increasing blood volume can significantly improve symptoms. Patients are often advised to drink 2-3 liters of water or other fluids per day and to dramatically increase their sodium intake to 3,000-10,000 mg per day (under a doctor’s supervision). This can be achieved through salt tablets or by liberally salting food.
• Compression Garments: Wearing waist-high compression stockings and/or an abdominal binder can help to manually squeeze blood from the lower body back up toward the heart.
• Graded Exercise Program: While exercise can initially worsen symptoms, a very slow and gradual exercise program is crucial for long-term improvement. It often starts with horizontal exercises (like a recumbent bike, rowing machine, or swimming) to build cardiovascular fitness without the stress of being upright. This is often done under the guidance of a physical therapist knowledgeable about POTS (such as with the Levine or CHOP exercise protocols).
• Lifestyle Adjustments: This includes avoiding prolonged standing, avoiding excessive heat, and eating small, frequent meals to prevent blood from being diverted to the digestive system.

2. Medications

Medications are used as a second-line treatment when non-pharmacological measures are not sufficient. There are no drugs specifically approved for POTS, so all medications are used “off-label.”

• Fludrocortisone: A steroid that helps the body retain salt and water to increase blood volume.
• Midodrine: A medication that constricts blood vessels to help prevent blood pooling.
• Beta-Blockers: Low doses of beta-blockers can be used to help blunt the excessive heart rate response.
• Ivabradine: A newer heart rate-lowering medication that can be effective for some patients.

I’ve seen significant improvement with non-drug strategies like increasing fluid and salt intake, wearing compression garments, and starting gradual recumbent exercise routines.

Postural Orthostatic Tachycardia Syndrome is a real and often debilitating disorder of the autonomic nervous system that can profoundly impact a person’s ability to engage with daily life. Its wide array of symptoms, from a racing heart to “brain fog,” makes it a classic “great imitator,” and its invisibility often leads to a long and frustrating journey to diagnosis. It is not a psychological condition, but a physiological one that requires understanding and a multi-faceted management plan. While there is no simple cure, a correct diagnosis can be a moment of profound validation. A proactive approach founded on increasing salt and fluid intake and a gradual, structured exercise program is the key to managing symptoms. Clinically, I emphasize a multidisciplinary approach and patient education while POTS is chronic, many patients regain function with consistent management.

Dysautonomia International. (n.d.). Postural Orthostatic Tachycardia Syndrome. Retrieved from http://www.dysautonomiainternational.org/page.php?ID=30

National Institute of Neurological Disorders and Stroke (NINDS). (2023). Postural Tachycardia Syndrome (POTS). Retrieved from https://www.ninds.nih.gov/health-information/disorders/postural-tachycardia-syndrome-pots

The Cleveland Clinic. (2023). Postural Orthostatic Tachycardia Syndrome (POTS). Retrieved from https://my.clevelandclinic.org/health/diseases/16560-postural-orthostatic-tachycardia-syndrome-pots