What is Postural Orthostatic Tachycardia Syndrome (POTS)?

If you’ve ever stood up and suddenly felt your heart racing, dizzy, or completely drained, you’re not imagining it. For people living with POTS, this is a daily reality. 

The good news? There are effective, evidence-informed strategies to help.

What Is POTS?

Postural Orthostatic Tachycardia Syndrome, commonly known as POTS, is a condition that affects the autonomic nervous system, which is the part of your nervous system that controls automatic body functions like heart rate, blood pressure, and circulation.

The hallmark of POTS is a significant increase in heart rate when moving from lying down or sitting to standing upright. For most people, the heart rate rises only slightly when they stand. In POTS, the heart rate jumps by 30 beats per minute or more within 10 minutes of standing, often accompanied by a cascade of uncomfortable symptoms.

Key Diagnostic Criterion for POTS

A heart rate increase of ≥30 bpm upon standing (or ≥40 bpm in adolescents), in the absence of a significant drop in blood pressure, sustained for at least 10 minutes — that’s the defining feature of POTS.

POTS is far more common than many people realise, and it disproportionately affects women, often emerging between the ages of 15 and 50. It can develop suddenly after a viral illness (including COVID-19), during pregnancy, following surgery, or after a period of prolonged bed rest.

What Does POTS Feel Like?

POTS presents differently from person to person, but the most commonly reported symptoms include:

• Racing or pounding heartbeat (palpitations)
• Lightheadedness or dizziness when standing
• Extreme fatigue and brain fog
• Shortness of breath, especially upright
• Fainting or near-fainting (pre-syncope)
• Headaches and visual disturbances
• Nausea and digestive upset
• Chest discomfort or tightness

These symptoms are often worse in the morning, after meals, in warm environments, or during prolonged standing. For some people, POTS is a minor inconvenience; for others, it is profoundly disabling and limits their ability to work, study, or carry out everyday tasks.

Why Does POTS Occur?

To understand why POTS happens, it helps to understand what normally occurs when you stand up. When you rise to your feet, gravity pulls blood toward your legs and lower body. Your autonomic nervous system quickly compensates,  it constricts blood vessels, slightly increases heart rate, and ensures adequate blood flow returns to the brain and heart.

In POTS, this compensation mechanism doesn’t work properly. Blood pools in the lower limbs, the brain and heart don’t receive enough blood, and the heart responds by beating much faster in an attempt to make up the difference. This is why the heart rate spikes,  it’s trying desperately to compensate for poor circulation.

The exact cause varies between individuals. Current research points to several contributing mechanisms:

1. Low Blood Volume

Many people with POTS have less total blood volume than normal (hypovolemia), meaning there’s simply less blood to distribute. When standing, this reduction becomes critically apparent.

2. Autonomic Nervous System Dysfunction

The autonomic nervous system — your body’s automatic control system — fails to send the right signals quickly enough. The “fight or flight” branch (sympathetic nervous system) may be overactive, while the “rest and digest” branch (parasympathetic nervous system) is underactive, tipping the body into a state of chronic physiological stress.

3. Poor Venous Return

Blood returning from the legs back to the heart may be impaired due to reduced muscle pump activity, poor vascular tone, or nerve dysfunction. This leaves blood pooling where it shouldn’t.

The Breathing Connection

Here’s something many people don’t realise: dysfunctional breathing patterns are extremely common in POTS  and they actively worsen symptoms. Over-breathing (hyperventilation), chest breathing, and breath-holding all disturb the delicate balance of oxygen and carbon dioxide in the blood, further dysregulating the autonomic nervous system and amplifying the very symptoms POTS already produces.

How Diaphragmatic Breathing Can Help POTS

The diaphragm is your primary breathing muscle, which is a dome-shaped muscle that sits at the base of your ribcage. When it works correctly, it moves downward as you inhale, gently massaging the abdominal organs, creating negative pressure that draws air into the lungs efficiently, and activates the parasympathetic “rest and digest” nervous system.

Unfortunately, many people,  and especially those with chronic illness, anxiety, or chronic pain, shift away from diaphragmatic breathing toward shallow chest breathing. This pattern is inefficient and stimulates the sympathetic nervous system, keeping the body in a heightened state of alert. For someone with POTS, this is a significant problem. Learn all about Dysfunctional Breathing here.

Why Diaphragmatic Breathing Matters for POTS

• Activates the vagus nerve: Slow, deep diaphragmatic breathing stimulates the vagus nerve, the primary pathway of the parasympathetic nervous system. This directly counteracts the over-active “fight or flight” response common in POTS, helping to calm heart rate and reduce the sense of panic.

• Improves venous return: When the diaphragm moves fully downward during inhalation, it acts like a pump, creating pressure changes that actively assist blood flow back toward the heart from the lower body, addressing one of the core problems in POTS.

• Regulates carbon dioxide (CO₂): Proper breathing maintains the right balance of CO₂ in the blood. CO₂ plays a vital role in dilating blood vessels and delivering oxygen to tissues. Over-breathing reduces CO₂ levels, causing blood vessels to constrict and reducing oxygen delivery to the brain,  making dizziness, brain fog, and breathlessness dramatically worse.

• Reduces sympathetic overdrive: Slow, rhythmic breathing at around 5–6 breaths per minute has been shown in research to increase heart rate variability (HRV), a measure of autonomic nervous system health, and reduce sympathetic nervous system dominance.

• Breaks the anxiety–symptom cycle: POTS symptoms are frightening. Fear and anxiety naturally follow, which further activates the sympathetic nervous system, which worsens symptoms. Diaphragmatic breathing is one of the most powerful tools available to interrupt this cycle.

How to Practice Diaphragmatic Breathing

If you have POTS, it’s best to begin breathing practice in a comfortable lying or semi-reclined position, where symptoms are typically less severe. As your tolerance builds, you can practise seated and eventually standing.

1. Get comfortable. Lie on your back with your knees bent, or sit in a supported chair. Place one hand on your chest and one hand on your belly, just below the ribcage.
2. Breathe in slowly through your nose. Allow your belly to gently rise,  your lower hand should move outward, while your chest hand stays relatively still. Aim for a gentle, unhurried inhale of about 4 seconds.
3. Exhale slowly through your nose or pursed lips. Let the belly fall naturally. The exhale should be slightly longer than the inhale,  around 5 to 6 seconds. Don’t force the air out, let it release softly. 
4. Find a comfortable rhythm. Aim for around 5–6 breath cycles per minute. This is slower than most people’s natural rate, and it takes practice. 
5. Practice consistently. Even 5–10 minutes of deliberate diaphragmatic breathing daily can begin to retrain your nervous system over time. Little and often is the key.

IMPORTANT NOTE

If you find that breathing exercises make you feel more lightheaded or unwell, stop and rest. This may indicate a significant breathing dysfunction that needs professional assessment before self-guided practice. This is exactly the kind of presentation we work with at Move Authentically Physiotherapy.

Breathing Retraining at Move Authentically Physiotherapy

At Move Authentically Physiotherapy, breathing retraining is a core part of how we support people living with POTS and other conditions driven by dysfunctional breathing. We know that changing how you breathe is not as simple as “just relax and breathe deeply”,  it requires careful assessment, education, and a progressive, personalised program.

Our physiotherapists assess your breathing pattern in detail: looking at mechanics, rate, volume, and how your breathing responds to movement and posture. From there, we build a retraining program specific to your body, your symptoms, and your goals. We work alongside your medical team to ensure a safe, integrated approach to your recovery.

You don’t have to manage POTS alone,  and you don’t have to simply “live with it.” Book your appointment with us today!