POTS Symptoms and Diagnosis: Signs, Tests and When to Get Help

By Anna Curran, RN, BSN, PHN · Last reviewed October 2026

POTS symptoms usually start or get worse when you stand up and get better when you lie down. The most common are a racing heart, dizziness or lightheadedness, fatigue, brain fog and feeling like you might faint. Doctors diagnose POTS by measuring how much your heart rate rises when you stand, along with your symptoms and history.

Many people with POTS wait months or even years for a diagnosis. Knowing the signs and the tests can help you have a clearer talk with your doctor.

Common POTS Symptoms

POTS affects the autonomic nervous system, which controls heart rate, blood pressure, digestion and sweating. That is why symptoms can show up all over the body. Cleveland Clinic and Dysautonomia International list these common symptoms:

Heart and circulation
– Racing or pounding heartbeat (palpitations), especially when upright
– Chest pain
– Shortness of breath
– Reddish-purple color in the legs, hands or feet when standing that fades when you lie down
– Cold or painful hands and feet

Brain and nerves
– Dizziness or lightheadedness
– Fainting or nearly fainting
– Brain fog and trouble concentrating
– Headaches
– Shakiness

Whole body
– Deep fatigue and exhaustion
– Trouble tolerating exercise
– Heavy sweating
– Poor sleep

Digestion
– Nausea
– Bloating
– Cramping

You do not need every symptom to have POTS. Symptoms vary a lot from person to person and from day to day.

What makes POTS symptoms worse?

Cleveland Clinic lists these common triggers:

Heat, including hot showers and hot days
Standing for long periods, such as in lines or while shopping
Strenuous exercise
Being sick
Menstrual periods

Large meals and alcohol can also worsen symptoms for some people, according to the Vanderbilt Autonomic Dysfunction Center.

How POTS Is Diagnosed

There is no single blood test for POTS. Diagnosis is based on heart rate changes with posture, plus your symptoms. Cleveland Clinic notes that diagnosis can take months to years because symptoms change over time.

The heart rate criteria

Doctors look for these main signs, based on expert guidance summarized in the Cleveland Clinic Journal of Medicine and by Dysautonomia International:

What doctors check	POTS pattern
Heart rate rise in adults	30 beats per minute or more within 10 minutes of standing (or above 120)
Heart rate rise in teens and children	40 beats per minute or more
Blood pressure	No large drop (not orthostatic hypotension)
How long symptoms have lasted	Frequent symptoms for at least 6 months

A fast heart rate on standing alone is not enough. Doctors also need to see symptoms that fit POTS and rule out other causes.

The active stand test

This test can often be done in a regular doctor’s office. Here is how it usually goes:

You lie down and rest for several minutes while your heart rate and blood pressure are checked.
You stand up.
Your heart rate and blood pressure are checked again at set times, such as 2, 5 and 10 minutes after standing.

Testing in the morning can make it more accurate, because symptoms are often stronger then. Dysautonomia International notes that the stand test can sometimes miss POTS. If your test is normal but your symptoms strongly fit POTS, your doctor may suggest more testing.

The tilt table test

The tilt table test is the main test used to diagnose POTS, according to Cleveland Clinic. Mayo Clinic describes it this way:

You lie flat on a padded table with a safety strap, for about 30 minutes.
The table tilts you to a head-up position.
Your heart rate and blood pressure are watched closely for about 10 minutes.

Some people feel dizzy or faint during the test. That is expected, and staff are there to lower the table if needed. If you know you get symptoms, let them know before you start.

Other tests you might have

Depending on your symptoms, your doctor may order:

Blood tests, such as a complete blood count and thyroid test
An electrolyte panel
An ECG (electrocardiogram) to check your heart rhythm
A heart monitor you wear at home
Sweat tests or a skin biopsy to check small nerves
Urine tests

Other Causes Doctors Rule Out

A fast heart rate when standing can come from other problems too. A 2019 review in the Cleveland Clinic Journal of Medicine lists conditions doctors should check for before diagnosing POTS:

Dehydration or low blood volume from illness, vomiting or not drinking enough
Anemia (low red blood cells)
Overactive thyroid (hyperthyroidism)
Electrolyte problems, such as abnormal sodium or potassium
Pheochromocytoma, a rare adrenal gland tumor that can cause a fast heart rate
Inappropriate sinus tachycardia, where the heart rate is high even at rest
Medicine side effects, including certain blood pressure medicines, water pills (diuretics) and some antidepressants
Long bed rest or deconditioning

Your doctor may also look for related conditions, such as Ehlers-Danlos syndrome or Sjögren’s syndrome, if you have signs of them.

Never stop a medicine on your own because you think it may be causing symptoms. Bring your full list to your doctor or pharmacist and ask them to review it.

How to Prepare for Your Appointment

A little planning can help your visit go well.

Keep a symptom log for 2 to 4 weeks. Note when symptoms happen, what you were doing and your position (lying, sitting or standing).
Track your heart rate. If you have a home blood pressure cuff or watch, record your heart rate lying down and again after standing for several minutes. Write down the times.
Note when it started. Did symptoms begin after a virus, COVID-19, pregnancy, surgery or an injury?
List your medicines and supplements.
Bring someone with you if brain fog makes it hard to remember details.

Home numbers are not a diagnosis, but they can help your doctor decide which tests to order. If your primary care provider is unsure, ask about a referral to a cardiologist or neurologist who treats autonomic disorders.

When to Call 911 or Go to the ER

POTS itself is usually not life-threatening, but some symptoms need emergency care because they could be something else, like a heart problem or stroke. Based on MedlinePlus guidance on fainting, call 911 if you or someone with you:

Faints and does not become alert within a couple of minutes
Faints and is hurt, bleeding or fell from a height
Has chest pain, pressure or discomfort
Has a pounding or irregular heartbeat with fainting
Has trouble speaking, vision problems or can’t move an arm or leg
Has a seizure, a tongue injury or loss of bladder or bowel control
Faints and is pregnant, has diabetes or is over age 50

Also get emergency help for severe shortness of breath or any symptom that feels different or much worse than your usual.

If you feel faint, lie down right away and raise your legs if you can. MedlinePlus advises staying lying down for at least 10 to 15 minutes after a faint, in a cool, quiet place if possible.

Frequently Asked Questions

Can POTS symptoms come and go?

Yes. Many people have good days and bad days. Symptoms often get worse with heat, illness, menstrual periods or long standing, and improve when those triggers pass.

Can a regular doctor diagnose POTS?

Often, yes. A primary care provider can do an active stand test in the office. Some people need a tilt table test or a referral to a cardiologist or neurologist who treats autonomic disorders.

Why is my blood pressure normal if I have POTS?

In POTS, blood pressure often stays about the same when you stand, while the heart rate jumps. A big drop in blood pressure points to a different condition called orthostatic hypotension.

Are POTS symptoms the same as anxiety?

They can feel similar, but they are not the same. POTS symptoms are tied to being upright and usually ease when you lie down. Doctors measure heart rate changes with posture to tell them apart.

The Bottom Line

POTS symptoms include a racing heart, dizziness, fatigue, brain fog and near-fainting that get worse when you stand and ease when you lie down. Diagnosis is based on a heart rate rise of 30 or more beats per minute in adults (40 in teens) within 10 minutes of standing, without a big drop in blood pressure. Doctors use an active stand test or tilt table test and rule out other causes like anemia, thyroid problems and dehydration. Call 911 for chest pain, fainting with injury or stroke-like signs.