What Is POTS? A Plain-Language Explanation

What happens when you stand

Gravity pulls blood toward your legs when you stand. Healthy bodies tighten blood vessels and nudge the heart rate up a little. In POTS, the heart rate climbs much more to make up for the shift.

The published criteria use a rise of at least 30 beats per minute within 10 minutes of standing (at least 40 for ages 12 to 19), with no large drop in blood pressure. Symptoms must happen often, ease when you lie down, and last at least 3 months. The 2019 NIH expert consensus and a 2026 JAMA review both state it this way.

How it feels

Lightheadedness, a pounding or racing heart, fatigue, brain fog, shakiness, nausea and trouble tolerating exercise or heat show up most often. The symptoms guide covers the full list.

Who gets it

Estimates run from 0.1% to 1% of people. The NIH panel notes that prevalence has never been studied well, and that no dedicated diagnostic code existed until 2022. The 24-month figure comes from a self-selected survey of 4,835 diagnosed patients, so treat it as a rough signal.

What counts as POTS

Several mechanisms can produce the pattern, and they often overlap: low blood volume, an over-active adrenaline response, changes in the small nerve fibers that control blood vessels, an autoimmune process in some people, and deconditioning after long illness or bed rest. The causes guide rates the evidence for each.

The Canadian Cardiovascular Society warns that people with standing symptoms but no fast heart rate, a fast heart rate but no symptoms, or another clear cause often get labeled with POTS when they have something else. Proper measurement guards against that.

The outlook

Studies disagree. In a Mayo Clinic follow-up of adolescents at about 5 years, 19% reported complete resolution and 86% had resolved, improved or had only intermittent symptoms. A Children's Hospital of Philadelphia survey of people with childhood-onset POTS found 99% still had some symptoms at around 10 years, and most still used non-drug measures. Both are surveys shaped by who chose to respond. Most people improve with treatment, many keep some symptoms, and the course varies a lot.

Where to go next

• Think you might have it? Read how to test at home, then check your numbers.
• Already diagnosed? Jump to treatment evidence and visit prep.