POTS: Why Your Heart Races When You Stand

Getting out of bed, taking a shower, or waiting in line can feel unexpectedly difficult when standing brings a pounding heart or lightheadedness. If this happens repeatedly, it deserves attention. There are several possible explanations; one is postural orthostatic tachycardia syndrome, usually called POTS. Symptoms alone cannot tell you which explanation fits. NHS

What happens in POTS?

POTS affects the body’s automatic control of circulation. It is a form of dysautonomia, meaning a problem with functions the nervous system usually manages without conscious effort.

When you stand, gravity shifts blood toward your legs and abdomen. Normally, your blood vessels and heart adjust to keep circulation steady. With POTS, the heart rate rises excessively while upright. Lower circulating blood volume, changes in blood-vessel tightening, and altered nerve signaling can contribute in different combinations. There is no single established cause that explains everyone. Johns Hopkins Medicine

What can it feel like?

Along with a racing or forceful heartbeat, people may notice:

Lightheadedness, shakiness, or feeling close to fainting.
Fatigue and difficulty tolerating everyday activity.
Trouble concentrating, sometimes called brain fog.
Headaches, blurred vision, nausea, or digestive symptoms.

Standing-related symptoms often ease when lying down. Heat and long periods upright may make them worse. Experiences range from manageable symptoms to major interruptions in school, work, and daily life. NHS

Not everyone with POTS faints. Anxiety can coexist with POTS, but a physical pattern of symptoms with standing should not be dismissed as anxiety alone. Johns Hopkins Medicine

How is POTS diagnosed?

A fast pulse by itself does not establish the diagnosis. Clinicians look for a consistent pattern that includes:

A sustained heart-rate increase of at least 30 beats per minute in adults, or at least 40 beats per minute for ages 12–19, within 10 minutes of moving from lying down to standing.
Frequent symptoms that worsen upright and improve when lying down.
Symptoms present for at least three months.
No sustained blood-pressure drop meeting criteria for orthostatic hypotension.
No other condition or medication effect that adequately explains the rapid pulse.

Both heart rate and blood pressure matter. The increase must be sustained across readings, rather than a brief spike. A smartwatch may provide useful observations, but it cannot check all these criteria. Do not repeatedly provoke near-fainting to collect numbers. CMAJ

Evaluation usually includes your history, an examination, measurements lying down and standing, an electrocardiogram, and selected blood tests. A clinician may consider dehydration, anemia, thyroid problems, medication effects, or another heart-rhythm condition. Some people need a tilt-table test or specialist assessment; others can be evaluated with a supervised standing test. NHS, JAMA

How does this connect with hypermobility?

POTS and hypermobile Ehlers-Danlos syndrome, or hEDS, can occur together. A study assessing people with POTS documented this overlap, but having either diagnosis does not establish the other. The relationship does not mean that every flexible person has POTS or that all dizziness in someone with hEDS comes from POTS. Each concern needs its own assessment. Miller and colleagues

Our Ehlers-Danlos article explains why flexibility, joint stability, and a clinical diagnosis are different things.

What can a care plan include?

Care should reflect your symptoms, blood pressure, other health conditions, and daily goals. Several approaches may be combined.

Fluids and salt, when appropriate. Increasing intake may help selected people with orthostatic problems, but it is not safe advice for everyone. High blood pressure, kidney disease, heart failure, or an existing fluid restriction change that decision. Ask your clinician what fits your situation before substantially increasing salt or fluids. CDC clinical guidance

Compression and practical adjustments. Properly selected garments that support the abdomen and legs may help circulation. Fit and tolerability matter. Reducing heat exposure and breaking up long periods of standing can also be part of a plan. JAMA

Movement adapted to your capacity. For some people, rehabilitation begins with seated or reclined activity. A knowledgeable clinician or physical therapist can adjust the approach to symptoms and any joint instability. Progress should follow your tolerance rather than a rigid schedule. Johns Hopkins Medicine

Special care when activity causes a delayed crash. Some people also have ME/CFS or another condition involving post-exertional malaise: a disproportionate worsening after physical or mental effort, often delayed by 12–48 hours and lasting days or longer. Tell your clinician if this happens. Pacing—balancing activity and rest within your limits—may be needed. Pushing through or automatically increasing exercise can worsen symptoms in people with this pattern. This caution does not mean everyone with POTS has ME/CFS. CDC activity guidance

Medication when needed. A clinician may consider medicines aimed at heart rate, blood-vessel tone, or blood volume. Selection depends on the individual, and many treatments still have limited trial evidence. Review prescriptions, over-the-counter products, and supplements together; do not stop or change a medicine based on this article. JAMA

How can you prepare for a visit?

Bring a short description of when symptoms began, what brings them on, and how they limit your day. Include current medicines and supplements, any fainting, and whether activity causes an immediate problem or a delayed crash. Existing pulse or blood-pressure records can help if you already have them; you do not need a wearable to be heard.

Questions worth bringing include:

What other explanations should we check?
Do I need an in-person standing test, ECG, or referral?
Which changes are safe with my blood pressure and other conditions?
How will we judge whether the plan is helping?

Our first-visit guide can help you organize that conversation. Telehealth can support history-taking and care coordination, while testing or urgent symptoms may require in-person care.

When should you seek urgent help?

Do not assume a new or severe symptom is simply a POTS flare. Call 911 for new or severe chest pain, severe shortness of breath, fainting with failure to recover promptly, or new difficulty speaking or moving. Fainting during exercise or while lying down also needs urgent assessment. Even after recovery, an unexplained faint deserves a clinical evaluation. NHLBI emergency guidance, NHS fainting guidance, American Heart Association

Living with symptoms that vary from day to day can be frustrating. Care can start with a careful account of your experience and a plan that respects your limits. The goal is steadier daily function, with follow-up guided by what is actually helping you.

General patient education; not an individual diagnosis or treatment plan. Information checked November 6, 2026.

Illustration: a conceptual depiction of standing and a noticeable heartbeat, not an anatomical or diagnostic image.

POTS: Why Your Heart Races When You Stand

What happens in POTS?

What can it feel like?

How is POTS diagnosed?

How does this connect with hypermobility?

What can a care plan include?

How can you prepare for a visit?

When should you seek urgent help?

References

Related articles

When Activity Makes You Feel Worse: Understanding Post-Exertional Malaise

Understanding Ehlers-Danlos Syndrome: Beyond Flexible Joints