What Is POTS? A Paediatric Cardiologist Explains Symptoms, Diagnosis and Treatment
This article is based on a Dokkcast conversation with Professor Piers Daubeney, Consultant Paediatric Cardiologist at the Royal Brompton Hospital and Professor of Paediatric Cardiology at Imperial College London.
What is POTS?
POTS stands for postural orthostatic tachycardia syndrome. Breaking down the name explains the condition itself: postural means positional, orthostatic means upright, tachycardia means a fast heart rate, and syndrome means a collection of symptoms.
According to Professor Daubeney, POTS is often used as a loose, catch-all term for anyone who feels "a bit faint." Clinically, though, it has a precise definition, and sits within a broader group of conditions involving dizziness, fainting and palpitations.
Who gets POTS?
POTS most commonly affects teenage girls, though it can persist into or emerge in adulthood. Professor Daubeney treats children up to the age of 18, and views paediatric POTS as distinct from the adult form of the condition.
In teenagers, a growth spurt is often a key factor. As young people gain height quickly, blood pressure can lag behind at childhood levels, and iron deficiency frequently makes symptoms worse. In adults, POTS is more often linked to a genuine, longer-term dysfunction of the autonomic nervous system (dysautonomia), rather than growth-related changes.
Reassuringly, most teenagers improve significantly by the end of their teenage years, whereas POTS in adults tends to be a longer-term condition to manage.
What causes the symptoms of POTS?
To understand POTS, it helps to understand basic circulation. The heart pumps blood out to the body — it doesn't actively pump blood back. Blood returns from the legs via veins running through the muscles, helped along by movement and muscle contraction (fidgeting, walking, and so on).
When someone stands up suddenly after lying or sitting for a while, gravity pulls blood down into the legs. If that person is also dehydrated, low in salt, iron-deficient, or has grown quickly, there may not be enough blood pressure to push that blood back up into the heart. The heart ends up "pumping on empty."
The body compensates in two ways:
The brain registers reduced blood flow as brain fog, dizziness, visual disturbance or ringing in the ears.
The heart beats faster to try to maintain output, which is felt as palpitations or a pounding heartbeat.
If blood pressure still can't be maintained, the brain can trigger a protective reflex via the vagal nerve — dropping blood pressure and heart rate sharply, causing a faint. Fainting brings the body horizontal, removing gravity as an obstacle and allowing blood to reach the brain again. In people with POTS, this reflex is simply "switched up high," making dizziness and fainting far more likely than in the general population.
Common symptoms of POTS
Dizziness on standing
Fainting or near-fainting
Palpitations (an awareness of a pounding or racing heart)
Brain fog and poor concentration
Fatigue
Red or discoloured lower legs and feet on standing
Symptoms are commonly triggered by getting up quickly from bed, standing in a hot shower, standing still for long periods (queuing, choir, assemblies), overnight flights, or sitting exams in a warm classroom.
How is POTS diagnosed?
Diagnosis starts with a detailed conversation to understand exactly what a patient experiences, and to rule out other causes. Professor Daubeney highlights two conditions that are routinely excluded first:
Iron deficiency — often linked to heavy periods (menorrhagia) in teenage girls, and a common standalone cause of fainting-type symptoms.
Addison's disease (adrenal insufficiency) — rare, but checked for via an early morning cortisol blood test.
Investigations typically include:
ECG – a baseline electrical recording of the heart
Echocardiogram – an ultrasound to rule out structural or congenital heart disease
Holter monitor – a 48-hour heart rate recording, worn at home, to capture heart rhythm during everyday symptoms
Tilt table test – lying on a table that is tilted upright while heart rate and blood pressure are measured continuously
The formal diagnostic threshold for POTS in under-18s is a heart rate increase of more than 40 beats per minute on standing (30 bpm in adults), sustained for at least six months, without a corresponding drop in blood pressure. Patients who faint or feel faint without this heart rate rise may instead be classed as having orthostatic intolerance — a related but distinct presentation on what Professor Daubeney describes as a spectrum, rather than entirely separate conditions.
How is POTS treated?
Management follows a stepwise approach, starting with lifestyle changes and escalating only if needed.
First-line lifestyle advice
Fluids – at least 1.5 litres of water per day
Salt – around one teaspoon of additional salt daily (a notable exception to general low-salt dietary advice, specific to this condition and age group)
Iron levels – checked and corrected, particularly in girls with heavy periods
Compression stockings – often reframed as "football" or "hockey socks" for teenage patients
Movement techniques – fidgeting the legs before standing, sitting on the edge of the bed first, and avoiding standing still after exercise (cooling down gradually instead)
Staying physically active – regular exercise strengthens not just skeletal muscle but the muscle within blood vessels, improving their ability to constrict and return blood to the heart
Escalating treatment options
If lifestyle measures aren't enough, treatment can progress through:
Slow-release sodium tablets
Medication to raise blood pressure, such as Midodrine (short-acting, taken as needed) or fludrocortisone (a steroid, taken as a regular course)
Medication to slow an excessively fast heart rate, such as ivabradine or a beta-blocker — only introduced once blood pressure support is already in place, since the fast heart rate is itself compensating for low blood pressure
What is the outlook for POTS?
The prognosis is described as excellent. Most teenagers respond well to lifestyle changes alone, and symptoms typically resolve as growth slows towards the end of the teenage years. A smaller group with more persistent symptoms can still achieve very good control by working through the treatment options above.
Adult-onset or adult-persisting POTS tends to be a longer-term condition, but is still very manageable with the right specialist input.
POTS and autonomic dysregulation
POTS is increasingly understood as a disorder of the autonomic nervous system rather than the heart itself. The autonomic nervous system has two branches: the "fight or flight" (sympathetic) system and "rest and digest" (parasympathetic) system, which together regulate heart rate, pupil size and other automatic body functions. An imbalance between the two is referred to as dysautonomia, and appears to underlie the poor blood vessel response seen in POTS.
Common myths about POTS
"POTS isn't real." It is a well-recognised, diagnosable condition with clear physiological mechanisms.
"POTS causes hypermobility, gut problems or mast cell issues." These conditions frequently occur alongside POTS, but POTS itself doesn't cause them — there is likely a shared underlying factor still being researched.
POTS and long COVID
Professor Daubeney notes a clear rise in POTS cases following the COVID-19 pandemic. This may relate to prolonged deconditioning after severe illness, fatigue associated with long COVID, or a direct viral effect on the autonomic nervous system — a pattern also seen historically after glandular fever (Epstein-Barr virus) and other viral infections.
Where to get help and support
Professor Daubeney recommends the STARS (Syncope Trust And Reflex anoxic Seizures) and POTS UK websites as reliable, high-quality resources for patients and families. He also recommends starting with a referral to a paediatric or cardiology specialist team, ideally with access to tilt table testing, for a proper diagnosis rather than relying on self-diagnosis via social media.
Key takeaways
POTS is a real, diagnosable condition involving an excessive heart rate rise on standing
It's most common in teenage girls, often linked to rapid growth and iron deficiency
Diagnosis typically involves an ECG, echocardiogram, Holter monitor and tilt table test
Treatment follows a stepwise approach — starting with fluids, salt, iron correction and compression, before medication if needed
The outlook for teenagers is excellent, with most improving by the end of their teens
Adults may need longer-term management, usually via specialist cardiology services
This article is for general information only and does not replace individual medical advice. If you or your child are experiencing symptoms of POTS, speak to your GP or a specialist for proper assessment and diagnosis.
Listen to the full conversation with Professor Piers Daubeney on the Dokkcast, wherever you get your podcasts.
