What is POTS (Postural Orthostatic Tachycardia Syndrome)?

The Unordinary Dietitian
6 days ago
5 min read

Blog overview on POTS: effects on heart rate, real symptoms, and treatment advice. Yellow background, orange swirl icons, text in white ovals.

POTS is a condition where your heart rate rises abnormally when you stand, because your autonomic nervous system struggles to regulate blood flow.

Postural Orthostatic Tachycardia Syndrome (POTS) is a form of dysautonomia, a condition involving dysfunction of the autonomic nervous system. The autonomic nervous system controls involuntary processes such as heart rate, blood pressure, digestion, temperature regulation, and sweating.

Dysautonomia is often described in two broad categories:

Vascular dysautonomia (sometimes referred to as “pipeline dysfunction”), where blood vessels do not constrict effectively
Cardiac dysautonomia (sometimes called “pump dysfunction”), where the heart rate response is dysregulated

POTS can fall into either or both categories depending on the underlying mechanism. Contributing factors may include low blood volume (hypovolemia), small fibre nerve damage, or excessively high adrenaline levels, which can lead to exaggerated increases in heart rate and sometimes blood pressure when moving to an upright position.

Who is this article for?

This article is for people who:

Experience dizziness, lightheadedness, or rapid heart rate when standing
Are exploring a possible POTS diagnosis
Live with POTS alongside conditions such as hypermobile Ehlers-Danlos syndrome (hEDS), Mast Cell Activation Syndrome (MCAS), ME/CFS, or migraine
Want practical, compassionate information that validates lived experience

How Is POTS Diagnosed?

POTS is typically assessed by measuring heart rate and blood pressure changes with posture. One commonly used assessment is the NASA Lean Test.

The test involves:

Lying down for 10–15 minutes
Standing upright while heart rate and blood pressure are monitored

A POTS diagnosis may be considered if there is:

A sustained increase in heart rate of 30 beats per minute (bpm) or more in adults (or 40 bpm in adolescents), or
A heart rate that exceeds 120 bpm when standing

If a significant drop in blood pressure occurs alongside the heart rate increase, this may indicate orthostatic hypotension, another form of dysautonomia.

What Happens in the Body With POTS?

When a person stands up, gravity causes blood to shift toward the lower body. In a healthy autonomic response, blood vessels constrict and heart rate adjusts slightly to ensure adequate blood flow to the brain.

In POTS, this compensatory response may be impaired. Blood can pool in the legs and abdomen, reducing blood flow to the brain and triggering symptoms such as dizziness, lightheadedness, and presyncope.

Diagram of a person sitting and standing, showing blood volume distribution in red. Text: "Blood volume sitting," "Blood volume standing." — Blood volume shifts in individuals with POTS, causing symptoms

Common POTS Symptoms

Note: Not everyone experiences all of these symptoms, and severity can change day to day.

POTS symptoms can vary widely and fluctuate day to day. Common symptoms include:

Lightheadedness or fainting when standing
Dizziness or presyncope with heat exposure, hot showers, positional changes, or weather changes
Venous pooling
Cold hands and feet
Excessive or reduced sweating
Tinnitus or visual disturbances
Chronic vestibular symptoms
Recurrent presyncope or syncope
Rapid heart rate or palpitations
Brain fog, fatigue, and poor concentration
Temperature dysregulation
Digestive issues and nausea
Bladder dysfunction
Anxiety or feeling “on edge” (often driven by physiological stress rather than psychological causes)

POTS, Blood Sugar and the Gastrointestinal System

It is common for individuals with POTS to experience dumping syndrome (rapid gastric emptying) and post-prandial POTS symptoms (an increase of POTS symptoms after eating). This can happen when food rich in carbohydrates move quickly from the stomach to the small intestine. When carbohydrate reaches the small intestine, specifically the duodenum, in the form of glucose, this causes the release of the hormone Gastric Inhibitory Peptide, that stimulates the release of insulin from the pancreas to regulate blood sugar, and it also causes vasodilation of your stomach. This dilation causes blood to run to your stomach from your brain to assist in digesting your food, causing symptoms of fatigue, sweating and dizziness. This process has also shown to cause post-prandial hyperglycaemia, which is a risk factor of developing type 2 diabetes.

POTS and Anxiety

POTS is not anxiety. There is a high prevalence of individuals who have been misdiagnosed for having anxiety instead of POTS due to the overlapping somatic signs of anxiety, such as heart palpitations and feeling faint or lightheaded. Additionally, the anxiety that may be experienced in this population has been found that it is due to the fear of symptom arousal and inability to manage their symptoms effectively.

What POTS Is Not

POTS is often misunderstood or misattributed. It is important to know that:

POTS is not “just anxiety”
POTS is not caused by deconditioning alone
Normal blood tests do not rule out POTS
Symptoms are physiological and real, even when they fluctuate

What Can Cause or Trigger POTS?

The exact cause of POTS is still not fully understood, however several factors increase risk.

POTS most commonly affects people assigned female at birth (AFAB) and typically presents between the ages of 15 and 50. It frequently co-occurs with conditions such as:

Hypermobile Ehlers-Danlos syndrome (hEDS)
Mast Cell Activation Syndrome (MCAS)
Myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS)
Migraine

Venn diagram with three circles labeled EDS, POTS, MCAS in blue, red, and purple. Arrows show connections, text describes related symptoms.

POTS may also be triggered by:

Viral infections (including COVID-19)
Concussion or traumatic brain injury
Hormonal changes (puberty, pregnancy, postpartum)
Major stressors such as surgery or physical trauma

A family history of POTS or related conditions may also increase risk.

Management of POTS

There is currently no single cure for POTS, however medications and lifestyle strategies can significantly reduce symptom burden and improve quality of life.

Management often focuses on supporting blood volume, circulation, and autonomic stability.

Lifestyle Strategies That May Help With POTS

You do not need to do all of these. Small changes can still make a meaningful difference. Pick what feels most achievable right now.

Hydration and Electrolytes

Aim for 2–3+ litres of fluids per day (individual needs vary)
Target 4–10 g sodium per day (equivalent to 4,000–10,000 mg sodium), under medical guidance
Use electrolyte supplements or salt tablets when appropriate
Ensure adequate intake of sodium, potassium, and magnesium

Compression Garments

Compression helps return blood from the legs and abdomen to the heart
Garments that include both abdominal and leg compression are more effective than legs alone
Start with lighter compression if higher grades are not tolerated

Temperature Regulation

Use cooling strategies in warm weather (spray bottles, cooling towels, vests, or pillows)
Avoid prolonged exposure to heat where possible

Movement and Exercise

Movement can support circulatory health, but tolerance varies significantly
Overexertion may worsen symptoms
Working with an exercise physiologist familiar with POTS can help tailor movement safely

Nutrition and Eating Patterns

Regular meals and snacks support blood sugar stability
Low GI carbohydrates may help reduce fatigue, brain fog, and dizziness
Sitting or reclining after meals may reduce symptom flares

Postural Strategies

Avoid standing still for long periods
Sit, lie down, or elevate legs when symptoms increase

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