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Doctor appointment handout

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How to prepare for a POTS assessment

POTS can cause brain fog, dizziness, palpitations, weakness, and near-fainting that becomes worse upright and improves after lying down. Diagnosis needs symptoms, timed heart-rate and blood-pressure measurements, at least three months of illness, and exclusion of anemia, thyroid disease, dehydration, medicines, and other causes.

Start here Record heart rate, blood pressure, symptoms, and time after standing, but do not test alone if you may faint or fall. Bring Timed standing readings, symptoms, device details, medicines, fluids, meals, sleep, periods, illness, earlier tests, and limited daily activities. Ask Do I meet every POTS criterion, what else could cause the upright tachycardia, and which treatment is safe for me? Know Adults use a 30-beat heart-rate rise and ages 12 to 19 use 40, but the heart-rate rise alone does not diagnose POTS.

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POTS and Brain Fog: Standing Test Appointment Guide, a doctor appointment handout from What Is Brain Fog.
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What to explain

Describe what changes when you stand

My brain fog, dizziness, palpitations, weakness, or near-fainting becomes worse after I stand and improves when I lie down. I brought heart-rate, blood-pressure, symptom, medicine, fluid, meal, and activity notes. Please help me check whether I meet POTS criteria, have another form of orthostatic intolerance, or have anemia, thyroid disease, dehydration, a heart rhythm problem, medicine effects, or another cause.

Questions to take in

Questions to ask your doctor

  1. Do my supervised standing results meet all POTS criteria, including symptoms for at least three months and no sustained orthostatic blood-pressure drop?
  2. Could anemia, low iron, thyroid disease, dehydration, infection, pain, prolonged bed rest, medicine effects, an arrhythmia, or another cause explain the tachycardia?
  3. Do I need an ECG, heart monitor, echocardiogram, active stand, tilt table, blood tests, or broader autonomic testing?
  4. Are standing catecholamines or antibody tests justified by a specific clinical concern, and what would the result change?
  5. What fluid and sodium plan is safe with my blood pressure, kidney and heart health, pregnancy plans, and medicines?
  6. Which compression type and exercise plan is safe, especially if I faint, have post-exertional symptom worsening, hypermobility, or another condition?
  7. Which medicine could help my main symptoms, what are the risks, and how long should we try it?
  8. Does temporary improvement after intravenous saline change diagnosis or treatment, or could the same response occur with dehydration or another condition?

Measurements and tests to discuss

What standing measurements and tests can show

A ten-minute active stand can record the heart-rate rise, blood pressure, symptoms, and recovery. Tilt testing, heart monitoring, blood tests, or broader autonomic testing should be chosen when the history or initial result leaves a specific question.

10-minute active stand or NASA Lean Test

A supervised active stand records heart rate, blood pressure, symptoms and time after standing. This page’s home check records heart rate, optional blood pressure and timing; write down symptoms separately. One home result does not establish a diagnosis.

Read the test guide

Tilt Table Test

Uses continuous monitoring during passive upright tilt. It may help when standing results are unclear or there's reason to think fainting has another cause, but not every diagnosis needs it.

Read the test guide

ECG and ambulatory heart monitor

ECG checks rhythm at one moment. A wearable medical monitor records rhythm during daily symptoms and may identify a fast or irregular rhythm that is not caused mainly by standing.

Ask your doctor

CBC, ferritin, TSH, and CMP

Checks common causes of tachycardia such as anemia, low iron, hyperthyroidism, dehydration, kidney problems, or electrolyte changes. The clinician may choose a smaller set based on symptoms.

Read the test guide

Autonomic Testing

May assess blood-pressure control, sweating, or another autonomic disorder when symptoms go beyond upright tachycardia. It is not required for everyone with suspected POTS.

Ask your doctor

Before the appointment

What to bring to the appointment

Three morning heart-rate and blood-pressure records after five to ten minutes lying down and during ten minutes standing. Test with someone nearby. End it if you feel faint.

Symptoms beside each reading, including brain fog, dizziness, palpitations, chest discomfort, breathlessness, weakness, nausea, shaking, vision change, and near-fainting.

The make and model of your cuff or heart-rate device, and whether you took readings before caffeine, nicotine, food, exercise, compression, extra fluid, salt, or morning medicines.

A list of every medicine and supplement, including stimulants, antidepressants, diuretics, blood-pressure medicines, decongestants, beta blockers, midodrine, fludrocortisone, and ivabradine.

A seven-day record of sleep, fluids, meals, heat, showering, periods, illness, activity, and how long symptoms improve after lying down.

Earlier ECG, heart monitor, echocardiogram, blood counts, ferritin, thyroid, kidney, electrolyte, glucose, and autonomic reports.

Any history of fainting, concussion from a fall, migraine, hypermobility, long COVID, autoimmune disease, diabetes, eating problems, heavy periods, pregnancy, or prolonged bed rest.

Three daily activities limited by standing, such as showering, cooking, shopping, school, work, exercise, or waiting in line.

One fast heart-rate reading does not diagnose POTS.

The clinician needs the change from lying to standing, repeated measurements over ten minutes, blood pressure, symptoms, illness duration, and exclusion of another cause. Heat, dehydration, meals, medicines, caffeine, nicotine, pain, and recent activity can change the result.

How the doctor assesses this

Details that help a clinician assess POTS

  • Brain fog and other symptoms repeatedly become worse upright and improve after lying down.
  • A supervised ten-minute stand shows the required sustained heart-rate rise without the blood-pressure drop of orthostatic hypotension.
  • Symptoms have lasted at least three months and are not explained by dehydration, anemia, thyroid disease, medicines, or another condition.

Signs of another cause

  • Symptoms do not become worse when upright or improve after lying down.
  • Repeated correctly performed standing measurements do not show the required sustained heart-rate rise.
  • Blood pressure falls by at least 20 mmHg systolic or 10 mmHg diastolic within three minutes. That supports orthostatic hypotension, not POTS.
  • Fever, pain, dehydration, blood loss, anemia, hyperthyroidism, prolonged bed rest, a medicine, substance use, or another condition explains the upright tachycardia.
  • The fast heart rate occurs at rest and is not mainly related to standing, which may require assessment for an arrhythmia or inappropriate sinus tachycardia.

What to understand before choosing care

Agree on tests and treatment

  • Please measure heart rate, blood pressure, and symptoms after lying down and during ten minutes of standing.
  • Please check whether another condition or medicine could cause the upright heart-rate rise before diagnosing POTS.
  • Anxiety can coexist with POTS, but anxiety alone does not produce the required sustained heart-rate change with standing.
  • If POTS is likely, I want a treatment plan that accounts for blood pressure, kidney and heart health, pregnancy, migraine, activity limits, and current medicines.
  • Please explain which treatment is meant to improve dizziness, fainting, brain fog, exercise tolerance, or heart rate and how we will measure benefit.

What the research found

What the criteria and research tell us

Current criteria require symptoms that are worse upright and have lasted at least three months. The heart rate must stay at least 30 beats per minute higher in adults or 40 higher in ages 12 to 19. There must be no lasting 20/10 mmHg blood-pressure fall and no better cause.

Heart rate varies with time of day, hydration, meals, heat, illness, medicines, caffeine, nicotine, and recent activity. A single wearable reading or one unsafe home test cannot diagnose POTS.

Tilt-table testing is not always necessary. A correctly performed supervised active stand can be enough. Tilt testing may help when the result is unclear or fainting seems to have another cause.

Small studies suggest brain fog can happen even while sitting or lying down, and heart rate alone may not explain it. Treatment research remains limited, so symptom response differs between people.

Improvement after fluid, salt, compression, lying down, or intravenous saline does not by itself confirm POTS or a specific subtype.

How age, sex and pregnancy affect care

For adults, one required criterion is a sustained heart-rate rise of at least 30 beats per minute within ten minutes of standing.

For ages 12 to 19, the heart-rate criterion is at least 40 beats per minute. Children and teenagers need pediatric assessment, growth review, school support, and safe activity planning.

POTS is most often diagnosed in adolescent girls and premenopausal women, but men, boys, older adults, and postmenopausal women can have orthostatic symptoms and still need proper assessment.

New upright symptoms in an older adult require careful review for medicines, dehydration, anemia, heart disease, neurological disease, and orthostatic hypotension rather than assuming POTS.

Pregnancy and postpartum blood-volume changes can alter symptoms and medicine safety. Discuss fluid, sodium, compression, and prescriptions with the obstetric and POTS clinicians.

If the answer is no

If your doctor will not test you for POTS

POTS is not diagnosed with one blood test. It requires symptoms that get worse upright, a measured rise in heart rate, and no large fall in blood pressure. Other causes of a fast heart rate also need checking. A doctor may start with a standing test and basic tests instead of a tilt-table test.

What changes the answer

  • Ask for a full standing test. Heart rate and blood pressure should be checked after 5 to 10 minutes lying down. They are then checked several times during 10 minutes of standing.
  • Bring the symptom timing. POTS symptoms are worse upright, improve after lying down, and last at least 3 months. Record dizziness, dim vision, shaking, weakness, or a racing heart when they happen.
  • Know the heart-rate rule. The rise must be at least 30 beats per minute in adults or 40 from ages 12 to 19. It must appear in at least two standing readings.
  • List other reasons your heart rate may rise. Fever, blood loss, anemia, dehydration, thyroid problems, long bed rest, and some medicines can also raise heart rate. These must be considered before a POTS diagnosis.
CMAJ: diagnosis and management of POTS

United States, United Kingdom, and Australia

Getting assessed

US United States

Ask primary care for ten-minute standing measurements. Bring symptoms and home readings. Ask for supervised heart rate and blood pressure, ECG, medicine review, and blood tests chosen for anemia, thyroid, dehydration, or another suspected cause.

  • Primary care can begin with history, orthostatic heart rate and blood pressure, ECG, medicine review, and selected blood tests.
  • An active stand can establish the required heart-rate response; tilt-table testing is useful in selected cases.
  • Cardiology, electrophysiology, neurology, or an autonomic clinic may help when diagnosis or treatment is difficult.
Read Heart Rhythm Society expert consensus and CMAJ diagnostic review
UK United Kingdom

Bring upright symptoms and readings to the GP. Ask for supervised heart rate and blood pressure over ten minutes, ECG, medicine review, and blood tests chosen for anemia, thyroid disease, dehydration, or another suspected cause.

  • The GP guide uses a sustained 30-beat rise for adults and 40 for teenagers with upright symptoms.
  • A ten-minute active stand records heart rate and blood pressure after lying down and during standing.
  • ECG and assessment for anemia, hyperthyroidism, orthostatic hypotension, and another cause are part of the initial review.
Read PoTS UK GP Guide
AU Australia

Ask the GP for a supervised active stand. Bring symptoms and readings. Ask for ten-minute heart rate and blood pressure, ECG, medicine review, and blood tests chosen for anemia, thyroid, dehydration, or another suspected cause.

  • Healthdirect states that diagnosis uses symptoms plus heart-rate and blood-pressure measurements while standing.
  • A GP may perform an active stand and refer to cardiology, neurology, or another appropriate service.
  • The Australian POTS Foundation published a detailed active stand guide for health professionals in 2025.
Read Healthdirect Australia and Australian POTS Foundation active stand guidance

Safety

Sit for daily tasks and record treatment effects

  • Record brain fog and other symptoms after lying down, sitting, and standing at the same time of day without deliberately pushing to faint.
  • Use the clinician-approved fluid and sodium plan. Record benefit, swelling, headache, blood pressure, and any breathing or kidney concern.
  • Record which compression garment you used, how long you wore it, and whether standing time, dizziness, or brain fog changed.
  • Follow a graded activity plan matched to your ability. Stop and report chest pain, fainting, severe breathlessness, or marked post-exertional worsening.
  • Plan seated versions of showering, cooking, dressing, school, or work until the cause and treatment are clear.

Source checked

Sources behind this handout.

  1. Raj et al., Diagnosis and Management of POTS (CMAJ, 2022)

    Source

  2. Breier et al., glucose challenge and gastrointestinal hormone responses in POTS (2022)

    Source

  3. Habek et al., Effect of Food Intake on Hemodynamic Parameters during the Tilt-Table Test in Patients with POTS (2019)

    Source

  4. Sheldon et al., Heart Rhythm Society expert consensus (2015)

    Source

  5. Ross et al., patient descriptions of brain fog in POTS (2013)

    Source

  6. PoTS UK, GP Guide

    Source

  7. PoTS UK, Children and Young People Consensus

    Source

  8. Healthdirect Australia, POTS

    Source

  9. Australian POTS Foundation, Active Stand Test guide (2025)

    Source