POTS diagnostic criteria: what your standing heart rate means - and how they're assessed
POTS is defined by your heart rate response when you stand up. What the Schellong test and NASA Lean test measure, which heart rate values count as indicators, and what a wearable can actually tell you.
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POTS - postural orthostatic tachycardia syndrome - is one of the few diagnoses where your heart rate response to standing is literally part of the definition. That makes a wearable that tracks heart rate potentially so relevant - as long as you understand what the numbers mean and what they don't. Sam helps you make sense of the bigger picture of daily data, for free.
The diagnostic criteria
In adults, POTS is indicated by a heart rate increase of more than 30 beats per minute within 10 minutes of standing up from lying down, or a standing heart rate of at least 120 beats per minute, with blood pressure remaining relatively stable throughout. That stable blood pressure is what separates POTS from orthostatic hypotension, where the blood pressure drops significantly instead. For adolescents aged 12 to 19, the threshold is higher because resting heart rates are naturally faster at that age: an increase of more than 40 beats per minute.
How the diagnosis is assessed
In Germany, the Schellong test is the established method: an active standing test that usually lasts 10 to 30 minutes, during which pulse and blood pressure are measured first lying down, then repeatedly while standing. The NASA Lean test, originally from aerospace medicine, is a similar method used mainly in research studies, where it is sometimes considered more sensitive than other methods at detecting heart rate changes.
A tilt-table test is used as a follow-up when a Schellong test gives unclear results, or when you have unexplained, recurring fainting episodes, or when there is suspicion of an underlying autonomic nerve problem. It's more involved because it's passive (with no muscular effort on your part), which rules out certain compensation mechanisms that an active standing test doesn't.
What a wearable can do - and cannot do
An active standing test is a deliberate, structured measurement: you watch your pulse in real time on your watch display while lying down and then standing up. This is independent of Sam and works with any watch that shows your pulse in real time.
One important caveat: a single test at home can be a signal worth discussing with your doctor - but it does not replace standardized diagnostic testing with a Schellong test, NASA Lean test, or tilt-table test, which also rule out other causes of a racing heart when standing.
Where Sam Health fits in
Sam reads your resting heart rate, sleep, and activity from Apple Health and compares them to your personal baseline, independent of any active standing test you might do on your own. Once a month, Sam summarizes trends in a report you can bring to your doctor appointment. For strategies that are considered basic treatment for POTS, see the article Living with POTS.
Try Sam HealthSam's role and limits
Sam is a wellness companion, not a medical device. Sam does not diagnose, treat, or prevent any illness and does not replace medical advice. For health questions, always consult a qualified medical professional.
Sources
- Clinical Practice Guide: Orthostatic Intolerance / POTS / Orthostatic Hypotension (mecfs.de)
- DocCheck Flexikon: NASA Lean Test
- DocCheck Flexikon: Postural Tachycardia Syndrome
Frequently Asked Questions
What heart rate changes count as a POTS indicator?+
In adults, an increase in heart rate of more than 30 beats per minute within 10 minutes of standing up, or a standing heart rate of at least 120 beats per minute - with stable blood pressure (no significant drop) - is considered an indicator. In adolescents aged 12 to 19, the threshold is higher: an increase of more than 40 beats per minute, due to naturally higher baseline heart rates in that age group.
How is POTS diagnosed - is an office test enough?+
The first step is usually a Schellong test, which is the established clinical standard in Germany and measures pulse and blood pressure while lying down and then standing, over 10 to 30 minutes. Where exactly this takes place depends on your clinic, but if the results are unclear, a tilt-table test typically follows at a specialized clinic or hospital.
How do the Schellong test and NASA Lean test differ?+
Both are active standing tests. The Schellong test is the clinical standard in Germany and typically lasts 10 to 30 minutes. The NASA Lean test, originally from aerospace medicine, is used mainly in research studies, where it is sometimes considered more sensitive than other methods at detecting heart rate changes - but it does not routinely replace the tilt-table test in clinical practice.
When is a tilt-table test ordered?+
A tilt-table test is used when a Schellong test gives unclear results, or when you have unexplained, recurring fainting episodes, or when doctors suspect an underlying autonomic nerve problem. It is more complex than an active standing test and is usually done in a specialized clinic or hospital.
Can Sam diagnose POTS?+
No. Sam does not perform standing tests and cannot diagnose POTS. A standing test is a deliberate, structured procedure that you discuss with your doctor. Sam passively reads resting heart rate, sleep, and activity data from Apple Health independently of any test.