If you’re experiencing symptoms such as dizziness, rapid heartbeat, or fatigue when standing, your healthcare provider may recommend autonomic testing to evaluate for Postural Orthostatic Tachycardia Syndrome (POTS).
Autonomic testing measures how well your autonomic nervous system regulates functions like heart rate and blood pressure—areas commonly affected in POTS.
In this article, we walk through what POTS is, why autonomic testing matters, the most common tests you may receive, and why it’s important to seek treatment providers who view POTS as a neurological—not just cardiovascular—condition.
We cover:
What Is POTS?
Postural Orthostatic Tachycardia Syndrome (POTS) is a form of dysautonomia—a disorder affecting the autonomic nervous system (ANS). The ANS regulates involuntary functions such as heart rate, blood pressure, digestion, temperature control, and blood vessel constriction.
When a healthy person stands up, the ANS automatically tightens blood vessels in the legs and briefly increases heart rate to maintain adequate blood flow to the brain. In POTS, this adjustment doesn’t work properly. Blood pools in the lower body, not enough blood reaches the brain, and the heart races to compensate.
This dysfunction causes a severe form of orthostatic intolerance, leading patients to experience common POTS symptoms:
- Rapid heartbeat when standing
- Dizziness or lightheadedness
- Fatigue
- Nausea
- Tremors or “jitters”
- Heat intolerance
- Chest pain
- Palpitations
- Fainting (syncope) or near-fainting
These symptoms can overlap with many other medical conditions, which is why autonomic testing is so important to confirm a diagnosis.
What Is Autonomic Testing?
“Autonomic testing” refers to a group of medical evaluations designed to assess how well the autonomic nervous system is functioning. Because POTS is fundamentally an autonomic disorder, this type of testing provides the most accurate picture of what’s happening physiologically.
Autonomic testing typically evaluates:
- Heart rate and blood pressure regulation
- The sympathetic and parasympathetic branches of the ANS
- Blood vessel constriction
- Sweat gland function
- Blood volume and hormone responses
No single test diagnoses POTS. Instead, clinicians use a combination of tests to understand how your body reacts to positional changes, physical stress, and autonomic activation.
Why Autonomic Testing Matters for Diagnosing POTS
Because POTS affects the ANS rather than the heart muscle itself, traditional cardiology tests may return normal results. This often confuses patients who feel severe symptoms despite “normal” cardiac workups.
Autonomic testing:
-
Identifies ANS dysfunction, which is the core issue in POTS
-
Helps distinguish POTS from related conditions like orthostatic hypotension, vasovagal syncope, small fiber neuropathy, or arrhythmias
-
Reveals contributing factors, such as low blood volume or abnormal hormone responses
-
Guides treatment decisions, including whether symptoms are hyperadrenergic, hypovolemic, neuropathic, or mixed in presentation
For many patients, autonomic testing is the long-awaited step that finally explains what’s happening in their bodies.
POTS Diagnosis and Types of Autonomic Testing
If your symptoms suggest POTS, your healthcare provider will begin with a detailed medical evaluation followed by specific diagnostic tests.
Initial Assessment
Before formal autonomic testing, your doctor will evaluate:
-
Symptom pattern: When symptoms began, how often they occur, and what triggers them (e.g., heat, stress, prolonged standing, dehydration).
-
Medical history: Autoimmune conditions such as Hashimoto’s disease, lupus, and Sjögren’s syndrome increase POTS risk.
-
Vital signs with position changes: Heart rate and blood pressure are measured while lying down, sitting, and standing. A significant rise in heart rate upon standing is a major diagnostic clue.
-
Lifestyle factors: Hydration, salt intake, sleep, and diet patterns may be discussed because they influence symptoms.
Active Stand Test
This is often the first test performed when POTS is suspected. It serves as a simpler, in-office alternative to the tilt table test.
The procedure is straightforward: you lie down for several minutes, then stand while your heart rate and blood pressure are recorded. Although the active stand test is less controlled and less precise than the tilt table test, it can still provide valuable information and help identify whether further autonomic testing is needed.
Tilt Table Test
The tilt table test is one of the most common and reliable ways to diagnose POTS. During the test, you lie on a table that gradually tilts upward to simulate standing. This safely triggers symptoms while clinicians closely monitor your heart rate response, blood pressure, and how you feel.
Patients are asked to report symptoms such as nausea, dizziness, chest discomfort, or feeling faint. In POTS, heart rate increases significantly upon tilting without a corresponding drop in blood pressure. This pattern helps distinguish POTS from conditions like orthostatic hypotension, which involves low blood pressure.
24-Hour Heart Rate Monitor
A 24-hour heart rate monitor is used to record heart rate and rhythm during normal daily activities. You wear the device for a full day and keep a log of symptoms and potential triggers—such as standing, exercise, meals, or dehydration.
Doctors analyze the data for patterns, including excessive heart rate increases when standing, which can support a POTS diagnosis. The monitor also helps rule out other causes of symptoms, such as arrhythmias.
Echocardiogram
An echocardiogram uses ultrasound imaging to create a detailed picture of the heart. It allows your doctor to assess chamber size, valve function, and how effectively the heart pumps blood. The test is painless and similar to an ultrasound used during pregnancy.
Most patients with POTS have normal echocardiogram results, which reinforces that POTS arises from autonomic dysfunction rather than structural heart disease.
24-Hour Urine Collection
Some patients are asked to collect urine over a 24-hour period to evaluate specific compounds related to blood volume and hormone activity.
-
Sodium: People with POTS often have low sodium excretion (sometimes below 170 mmol per 24 hours). This may indicate that the body is retaining salt and water in an attempt to increase blood volume.
-
Norepinephrine and epinephrine: Measuring these hormones helps rule out adrenal tumors (pheochromocytoma) and can identify forms of POTS associated with elevated catecholamines.
Blood Tests
Although no blood test can diagnose POTS on its own, doctors may order bloodwork to rule out other conditions such as anemia, electrolyte imbalances, or thyroid dysfunction.
Blood samples may be taken while lying down and again after standing—sometimes during a tilt table test. Elevated norepinephrine levels upon standing can support a POTS diagnosis. Some blood tests also help assess overall blood volume, which is often low in certain POTS subtypes. Identifying low blood volume can guide treatment choices such as increased fluid intake, salt supplementation, or medication.
Sweat Tests
Sweating is controlled by the autonomic nervous system, so abnormal sweat responses may indicate autonomic dysfunction.
Two common sweat tests include:
Quantitative Sudomotor Autonomic Reflex Testing (QSART)
Also known as the axon reflex test, QSART measures how small nerve fibers control sweat gland response to stimulation. A mild electrical current is applied to the skin on the arms and legs to trigger sweating. Patients with POTS may show reduced or excessive sweating.
Thermoregulatory Sweat Test (TST)
A color-changing powder is applied to the skin, and the patient is placed in a warm, controlled chamber. As body temperature rises, the powder reveals where and how much a patient sweats. People with POTS often show absent or abnormal sweating patterns.
Hand Grip Test
During this test, you squeeze a handgrip dynamometer to measure maximum strength, then maintain a percentage of that strength until fatigued. This activates the sympathetic nervous system (SNS). Patients with POTS often exhibit an exaggerated increase in blood pressure during this task, which provides insight into SNS function.
Valsalva Maneuver
For this test, you exhale forcefully against a closed airway while connected to heart rate and blood pressure monitors. The Valsalva maneuver evaluates how autonomic nerves regulate cardiovascular responses under pressure. Patients with POTS often show a heightened or irregular blood pressure response.
Where Can You Get Autonomic Testing for POTS?
Autonomic testing requires specialized equipment and training. It is most commonly offered through:
Primary care providers typically cannot perform autonomic testing themselves, but they can provide referrals to clinics that do.
Because demand is high and specialists are in short supply, wait times can be long. Preparing symptom logs, medical history, and prior testing results can help streamline the process.
After Diagnosis: What Patients Need to Know About Finding Effective POTS Treatment
Finding effective care for POTS can be more challenging than you would expect. Many patients try everything they’re told—drink electrolytes, wear compression socks, do gentle exercise—yet still find themselves dealing with dizzy spells, brain fog, and exhaustion that never seems to fully go away.
That’s because most healthcare providers approach POTS as a cardiovascular issue—focusing on heart rate, blood pressure, and blood flow—without treating the underlying neurological systems that became unstable in the first place.
So, when choosing a POTS treatment provider, whenever possible, choose one that understands and treats this neurological root cause. With tailored neurological therapy, it is possible to retrain your autonomic nervous system, providing long-term regulation gains and sustainable quality-of-life improvements (not just short-term symptom relief). This is the approach we take to treating POTS at Cognitive FX.
Read this article to learn more about how to evaluate POTS treatment providers.
Treating the Neurological Root Causes of POTS at Cognitive FX
Our 4-day program grew out of the success we’ve had treating concussion patients who commonly experience POTS symptoms. As we consistently saw their autonomic function improve through neurological rehabilitation, we refined and formalized those methods into a dedicated POTS treatment.
The Four-Day POTS Treatment Program
Cognitive FX does not diagnose POTS or perform autonomic testing, but we offer an intensive, four-day POTS treatment program for patients who already have a confirmed diagnosis.
Our approach focuses on retraining autonomic regulation using a carefully designed set of therapies that target different components of ANS dysfunction:
- Comprehensive neurological and physiological assessment
- Neuro-cardio training
- Vestibular recalibration
- Breathing mechanics training
- Cranial nerve activation
- CO₂-based therapies
Each modality addresses a different dimension of autonomic regulation, helping the brain relearn how to communicate effectively with the cardiovascular system.
Neuro-Cardio Training
POTS patients often remain stuck in sympathetic overactivation. Our interval-based approach alternates short bursts of exertion (activating the sympathetic system) with guided recovery strategies—cooling, diaphragmatic breathing, and sensory inputs—to activate the parasympathetic system. Repeating these cycles teaches smoother transitions between “fight-or-flight” and “rest-and-digest.”
Vestibular Recalibration
A small inner-ear structure called the saccule helps the brain detect vertical movement. When saccular signaling is inaccurate, the brain may overreact to posture changes, causing dizziness or tachycardia. Our vestibular therapy helps recalibrate these signals and reduce symptom spikes during movement.
Breathing Mechanics Training
Breathing directly affects autonomic tone. Many POTS patients breathe shallowly and chronically lower their CO₂ levels, worsening dizziness and fatigue. We teach deep breathing through the diaphragm and use supplemental CO₂ when appropriate to restore balance.
Cranial Nerve Activation
Taste and smell exercises (lavender, vanilla, citrus, mint, and others) stimulate parasympathetic or sympathetic pathways. Activating these cranial nerves helps reinforce healthy autonomic signaling.
CO₂-Based Therapies
CO₂ is essential for oxygen delivery. Many POTS patients run low on CO₂, limiting their ability to tolerate exercise. We use CO₂ inhalation to prepare patients for cardio intervals, and a CO₂ “bath” afterward to enhance relaxation and recovery.
Each therapy targets a different aspect of dysautonomia, teaching the brain how to self-regulate more effectively. Each patient is provided with education about what POTS is and how neuro training helps.
If you’ve been diagnosed with POTS and you live in the Utah Valley area—or can travel to Provo—our clinic offers one of the few neurologically focused POTS treatment programs in the country. Fill out this form to see if you’re a good fit for our program or call our patient care coordinator at 385-334-6093.
