What Is POTS (Postural Orthostatic Tachycardia Syndrome) and Why Does It Cause Dizziness Upon Standing?

Understanding POTS: When Standing Up Triggers a Rapid Heartbeat

Have you ever felt your heart racing or your head spinning the moment you stand up from sitting or lying down? This could be a sign of Postural Orthostatic Tachycardia Syndrome (POTS) – a condition that affects blood flow and the body’s ability to regulate heart rate and blood pressure when changing positions.

POTS is a form of dysautonomia, meaning it involves dysfunction of the autonomic nervous system (ANS) – the part of the nervous system that controls automatic functions like heart rate, blood pressure, and blood vessel constriction.

When a healthy person stands up, blood briefly pools in the legs due to gravity, and the ANS quickly compensates by tightening blood vessels and slightly increasing the heart rate to maintain adequate blood flow to the brain. If you have POTS, this regulation doesn’t work efficiently. Your heart rate may increase by more than 30 bpm or exceed 120 bpm within 10 minutes of standing without a corresponding drop in blood pressure, causing symptoms like lightheadedness, palpitations, fatigue, or even fainting.

Key Symptoms of POTS

POTS can manifest differently among individuals, but common signs may include:

Dizziness or lightheadedness upon standing
Rapid heart rate (tachycardia) – often >110 bpm while upright
Fatigue and exercise intolerance
Palpitations or “pounding” heartbeat
Brain fog or difficulty concentrating
Shortness of breath
Nausea or GI discomfort
Cold or blotchy hands and feet

These symptoms tend to worsen with heat, dehydration, prolonged standing, or sudden postural changes.

Types of POTS

Researchers recognize several subtypes of POTS based on the dominant underlying mechanism:

Neuropathic POTS:
Caused by peripheral nerve damage that impairs blood vessel constriction in the legs, leading to excessive blood pooling.
Hyperadrenergic POTS:
Marked by an overactive sympathetic nervous system and elevated norepinephrine levels, resulting in high heart rate, tremors, and anxiety-like symptoms.
Hypovolemic POTS:
Characterized by low blood volume, which can worsen dizziness and heart rate instability.
Secondary POTS:
Develops as a consequence of another condition, such as autoimmune disorders, diabetes, long COVID, Ehlers-Danlos Syndrome (EDS), or chronic fatigue syndrome.

Why Does POTS Cause Dizziness When Standing?

The hallmark dizziness or “head rush” in POTS arises from reduced blood flow to the brain upon standing. When you rise quickly, gravity causes about 500–1000 ml of blood to pool in the lower body. In healthy individuals, the ANS corrects this within seconds. But in POTS patients, the blood vessels fail to constrict efficiently, and the heart compensates by beating faster – often exceeding 120 bpm at rest or early in standing posture.

Despite this rapid heart rate, the brain may still receive less oxygenated blood, leading to symptoms like dizziness, blurred vision, or near-fainting episodes.

Common Triggers and Causes of POTS

While the exact cause of POTS remains multifactorial, several triggers and risk factors have been identified:

Viral infections (including COVID-19)
Autoimmune conditions such as lupus or Sjögren’s syndrome
Deconditioning or prolonged bed rest
Hormonal fluctuations, particularly in young women
Genetic predisposition
Low blood volume or hypovolemia
Chronic stress or anxiety disorders

Emerging research also indicates that POTS is more common in women aged 15–50, possibly linked to hormonal influences on autonomic regulation.

Diagnosis: How Is POTS Identified?

Diagnosing POTS often involves ruling out other conditions that cause similar symptoms, such as thyroid disorders, low blood pressure, anemia, or dehydration.
Common diagnostic steps include:

Tilt Table Test:
The gold standard for POTS diagnosis. The patient is strapped to a table that tilts upright, and continuous ECG and blood pressure monitoring assess changes upon standing.
Active Stand Test:
Heart rate and blood pressure are recorded while lying down, then after standing for 10 minutes. A heart rate rise ≥30 bpm (or ≥40 bpm in teens) without hypotension suggests POTS.
Blood Volume and Norepinephrine Levels:
These may be measured to identify hypovolemic or hyperadrenergic subtypes.
Continuous ECG Monitoring:
Continuous or wearable ECG devices help track abnormal heart rate patterns in daily life, distinguishing between episodic tachycardia and persistent autonomic imbalance.

Treatment Options for POTS

There’s no single cure for POTS, but symptoms can be managed effectively with lifestyle modifications and, when necessary, medications.

Lifestyle and Non-Pharmacologic Strategies

Increase Fluid and Salt Intake: Boosting blood volume can help stabilize blood pressure.
Compression Garments: Support stockings reduce blood pooling in the legs.
Gradual Exercise Programs: Recumbent cycling and swimming build tolerance.
Avoid Prolonged Standing, Sitting or Heat Exposure.
Elevate the Head of the Bed: Reduces overnight fluid shifts.

Medical Treatments

Beta-blockers to reduce heart rate
Fludrocortisone to increase fluid retention
Midodrine to constrict blood vessels
Ivabradine (in selective cases) for heart rate control
SSRIs or SNRIs to modulate autonomic function

Each treatment plan is individualized based on symptom patterns and POTS subtype.

The Role of Long-Term ECG Monitoring in POTS Management

Devices like the FDA-cleared, medical grade Frontier X Plus allow long-term ECG monitoring, enabling patients and clinicians to visualize heart rate fluctuations and rhythm changes throughout the day – especially during posture shifts, exercise, or recovery.

Unlike standard Holter monitors that capture data for only 24 hours, the Frontier X Plus enables long-term ECG (24 h per 30 min of charge) and heart rate tracking over extended periods. It is cleared for detecting cardiac rhythm irregularities such as atrial fibrillation (AFib), tachycardia, and bradycardia, while also helping users and clinicians observe physiological patterns – such as heart rate changes during posture shifts – that may warrant further evaluation.

By combining ECG trends with activity and posture data, users gain a deeper understanding of how daily habits and triggers influence their heart’s autonomic response, allowing better management and lifestyle adjustment.

Living with POTS: Adapting and Thriving

While POTS can initially feel overwhelming, understanding the condition empowers individuals to take control of their symptoms. With the right combination of hydration, diet, gradual exercise, and continuous monitoring, many people with POTS can return to full activity levels.

The key lies in tracking your body’s signals – both mechanical (through posture and activity) and electrical (through ECG and heart rate) – to manage the delicate balance of your autonomic system.

Key Takeaways

POTS is a form of autonomic dysfunction causing excessive heart rate increase upon standing.
Common symptoms include dizziness, palpitations, and fatigue.
Diagnosis relies on tilt table tests and continuous ECG monitoring.
Hydration, salt intake, compression, and graded exercise are first-line treatments.
Devices like Frontier X Plus enable long-term ECG tracking to personalize therapy and identify triggers.

SEO-Optimized FAQs

Q1: What causes POTS syndrome?
POTS occurs when the autonomic nervous system fails to regulate blood flow properly upon standing, often due to neuropathy, low blood volume, or an overactive sympathetic response.

Q2: Why does my heart rate increase when I stand up?
Standing causes blood to pool in the lower body. In POTS, blood vessel constriction is impaired, forcing the heart to beat faster to maintain blood flow to the brain.

Q3: How is POTS diagnosed?
A tilt table test or active stand test measuring heart rate and blood pressure changes helps confirm POTS. Continuous ECG monitoring can support diagnosis by tracking heart rate patterns in real life.

Q4: What is the treatment for POTS?
Treatment includes lifestyle adjustments like increasing fluid and salt intake, wearing compression garments, and in some cases, medications such as beta-blockers or fludrocortisone.

Q5: Can long-termECG monitoring help with POTS?
Yes. Devices like Frontier X Plus continuously track heart rate and rhythm changes, offering insights into postural responses and helping optimize treatment plans.