How do I recognise PoTS?

What PoTS is

Postural orthostatic tachycardia syndrome (PoTS) is a disorder of the autonomic nervous system. When you stand up, your heart rate rises far more than it should, and you feel unwell – without your blood pressure dropping. It affects an estimated 0.1 to 1 % of the population, mostly women between 15 and 45. In 30 to 40 % of cases the symptoms begin within three months of an infection (SARS-CoV-2, Epstein-Barr virus, influenza); other triggers are surgery, pregnancy, injury or a long period of bed rest. The median delay to diagnosis is still about two years.

Typical symptoms

• Light-headedness, dizziness or “greying out” within minutes of standing, worse the longer you stand
• A racing or pounding heart on standing or with light activity (climbing stairs, showering, housework)
• Marked fatigue and poor exercise tolerance; recovery from exertion takes unusually long
• “Brain fog” – difficulty concentrating, finding words, remembering
• Tremulousness, sweating, nausea, headache, blurred vision, purple or cold hands and feet when upright
• Symptoms improve when lying down; heat, large meals, dehydration, alcohol and prolonged standing make them worse
• Near-fainting; actual fainting is less typical and should prompt a cardiological assessment

The diagnostic criterion

According to the international consensus criteria, PoTS requires chronic symptoms of orthostatic intolerance (usually for at least three months) together with a sustained rise in heart rate of at least 30 beats per minute (at least 40 in adolescents aged 12–19) within 10 minutes of standing or head-up tilt, without orthostatic hypotension (a fall in blood pressure of 20 mmHg systolic or 10 mmHg diastolic or more). The standing heart rate is often above 120. A single high reading is not enough; the rise must be reproducible and explain the symptoms.

What must be ruled out first

A fast heart rate on standing has many causes. Before PoTS is diagnosed, the following should be considered and, where appropriate, tested: thyroid disease, adrenal insufficiency, phaeochromocytoma, anaemia, dehydration, heart muscle, valve or congenital heart disease, chronic lung disease, and medication effects (stimulants, some antidepressants, diuretics). Typical first steps are a thorough history, physical examination, resting ECG, blood tests, and in many cases a 24-hour ECG and an echocardiogram.

One question that changes the treatment plan

Ask yourself: after physical or mental exertion, do I get markedly worse 12 to 48 hours later, for a day or more? This is called post-exertional malaise (PEM). It is the hallmark of myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) and is common in post-COVID PoTS. PoTS without PEM is treated with a stepwise exercise programme; PoTS with PEM is not – here pacing comes first. Read more in Exercise training in PoTS – 20 years on.

When to see a doctor – and when urgently

See your general practitioner if symptoms have lasted more than a few weeks or limit your daily life. Seek urgent care if you have chest pain, fainting with injury, a resting heart rate persistently above 120, severe shortness of breath, or new neurological symptoms such as weakness, speech or vision problems.