Postural orthostatic tachycardia syndrome (POTS) is a form of dysautonomia or dysfunction of the autonomic nervous system (ANS) that causes debilitating and unpredictable lightheadedness and rapid heart rate upon standing.

Although often missed, POTS impacts one to three million Americans, with a growing number of patients experiencing POTS after recovering from COVID as well.

The ANS consists of three major divisions: the sympathetic and parasympathetic branches and the enteric nervous system. Together, these control “automatic” functions that you do not consciously think about, such as heart rate, blood pressure, digestion, pupil dilation and constriction, kidney function, and temperature control. Since the ANS is responsible for regulating most of the largely automatic functions, dysautonomia can impact the ability to regulate temperature, heart rate, breathing, and sweating.

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POTS Signs & Symptoms

Presentation varies, but generally, patients have trouble regulating ANS functions like heart rate and blood flow.

This results in symptoms like

• lightheadedness
• fainting
• abnormal heart rate
• palpitations or fluttering in the chest
• fatigue
• exercise intolerance

Fluctuations in heart rate and blood flow resulting from underlying dysfunction of the nervous system contribute to additional neurologic symptoms such as:

• difficulty concentrating
• headaches
• tremulousness
• and sleeping difficulties

Since the ANS is closely intertwined with the nervous system in the gastrointestinal tract via the gut-brain axis, dysfunctional control of automatic functions can also cause GI symptoms such as:

• nausea,
• constipation,
• diarrhea,
• and malnutrition

Some patients experience dysfunctional bladder control, leading to excessive urination or nighttime urination. Skin rashes, flushing, or pallor may also occur. These symptoms can vary day-to-day and make it difficult to carry out everyday activities.

Diagnosis is based on symptoms and a persistent increase in heart rate of at least 30 beats per minute, measured during the first 10 minutes upon standing or sitting upright without a drop in blood pressure, in the absence of dehydration or blood loss.

This is assessed by recording heart rate and blood pressure when the patient is lying down during a 10-minute standing test or via autonomic testing using a Tilt Table Test.

POTS Possible Causes

POTS is a collection of symptoms with a variety of underlying causes. It commonly follows viral or bacterial infections, including Lyme disease, Epstein Barr virus, Mycoplasma pneumonia, and SARS-CoV2.

It can also be brought on by stressors like injuries, surgeries, chemical or mycotoxin exposures, or traumatic events. As well as occur due to imbalances of vitamins like vitamins E, B1 (thiamine), B3 (niacin), B6 (pyridoxine), and B12 that are essential to nerve function.

Research suggests some patients develop POTS due to an autoimmune response where the body makes antibodies against its tissues, such as ANS receptors.

POTS patients and their close relatives show a higher prevalence of other autoimmune conditions like celiac disease, Hashimoto’s thyroiditis, systemic lupus erythematosus (SLE), and Sjögren’s syndrome.

Another root cause of POTS is sympathetic ANS dysfunction. The sympathetic branch (“fight or flight” response) prepares the body for demands and emergencies. It stimulates organs and glands so the body can flee or fight off danger, including increased heart rate and blood to skeletal and cardiac muscles.

Some patients have a hyperadrenergic form of POTS with overactivity of the sympathetic nervous system resulting in elevated stress hormone norepinephrine/noradrenaline.

This causes symptoms like tremors, anxiety, elevated blood pressure, and cold sweaty while upright and may be associated with mast cell reactivity.

Along with mast cell dysfunction, POTS is often associated with genetic connective tissue disorders like Ehlers-Danlos syndrome.

Genetic variants in NOS3 and ADRB2 genes are also associated with POTS.

Functional Medicine Labs to Test for POTS

A functional medicine approach to evaluating symptoms suggesting ANS imbalances should rule out other conditions that could explain or mimic them, such as adrenal or thyroid disorders, anemia, dehydration, and nutrient or electrolyte imbalances.

Testing for Adrenal Function

With stressors like imbalanced blood sugar, infections, or emotional stress, the adrenals secrete cortisol. Cortisol should be measured throughout the day to ensure it’s rising and falling appropriately with the Adrenal Function Profile.

The adrenals also release aldosterone, which regulates sodium, potassium, and water and helps stabilize blood pressure. A Comprehensive Neurotransmitter Profile can look at additional markers, including norepinephrine, epinephrine, and histamine.

Testing for Thyroid Dysfunction

If thyroid dysfunction is clinically suspected, a Complete Thyroid Panel including thyroid-stimulating hormone (TSH), T3 (free and total), T4 (free and total), reverse T3, and anti-thyroglobulin and thyroid peroxidase antibodies can be assessed using functional medicine ranges.

Testing for Hydration, Blood Sugar, and Electrolyte Balance

A comprehensive metabolic profile (CMP) can assess electrolytes, blood glucose, and kidney and liver health.

Testing for Micronutrient Deficiencies

Nutrient deficiencies, such as B vitamins, magnesium, Vitamin D, and iron, can be assessed using blood spot tests, nutrient profiles, and CBC. The Metabololomix+ by Genova Diagnostics provides a non-invasive assessment of B-vitamins, antioxidants, minerals, digestion, fatty acids, and amino acids.

Testing for Food Sensitivities

In response to food sensitivities, the body releases histamine and inflammation that trigger the adrenals to produce epinephrine, creating a functionally hyperadrenergic state with POTS symptoms.

Testing Gut Health

A comprehensive stool test can provides a comprehensive analysis of gut health, including SigA and Anti-gliadin SIgA, calprotectin for inflammation, and bacteria, parasites, viruses, yeast, and other intestinal health markers.

Other Useful Test

A Tick-Borne Disease Panel can look further for infections associated with nervous system autoimmunity and POTS.

Cardiac Abnormalities

In addition to Tilt Table Testing for pulse and blood pressure changes during standing, cardiac issues, including abnormalities in the heart’s electrical system, can be assessed using an electrocardiogram (EKG) or ECHO.

Functional Medicine Treatment for POTS

Managing POTS requires a multidisciplinary approach that addresses identified underlying causes and modulates symptoms. Conventional treatment aims to increase blood volume with fluids and electrolytes, control heart rate, and cause peripheral vasoconstriction with medications. The presentation of dysautonomia is heterogeneous, so treatment must be individualized.

Volume Expansion

Consuming water with salt or electrolytes is effective for long-term volume expansion. Maintaining adequate hydration raises norepinephrine, helping to maintain blood pressure and control symptoms. Patients with hypovolemic symptoms should gradually increase salt and water intake, adjusted for individual needs.

Himalayan and Celtic salts contain minerals along with sodium to support adrenal function and blood volume without anti-clumping agents, added iodine, and other additives found in table salt.

Natural electrolyte powders or organic coconut water contain potassium, sodium, chloride, and carbohydrates to support hydration.

*Note: Increased water and salt intake should be avoided with kidney disease, heart failure, and hyperadrenergic POTS.

Elevating the head of the bed 4-6 inches places the body at a slight angle during sleep to increase blood volume over time by creating mild orthostatic stress. This shifts fluids to the lower body and decreases central and effective circulating blood volume to activate the renin-angiotensin-aldosterone system, leading to salt-water retention and volume expansion.

Reduction in Venous Pooling

Patients with dysfunctional vascular tone can have increased venous pooling in the legs when upright. They may benefit from lower body gradient compression garments extending to the upper abdomen or abdominal binders.

Exercise

‍Structured exercise programs featuring aerobic conditioning with lower-body resistance training supports POTS patients.

Proper Nutrition

POTS patients often do best eating several smaller meals since blood is redirected to the gut after eating large meals to facilitate digestion which can exacerbate symptoms.

Many experience fewer symptoms when limiting simple carbohydrates and balancing meals with protein, healthy fats, and complex carbohydrates to balance insulin.

Insulin is released when consuming carbohydrates to maintain constant blood sugar. Insulin also has vascular impacts, altering blood flow and contributing to vasodilation, especially in the gut.

Avoiding allergenic foods and common food sensitivities can also help symptoms.

Stress Reduction

Stress exacerbates ANS imbalances. Therefore, daily relaxation techniques such as breathing, meditation, gentle stretching, and mindfulness practices can help.

Summary

A properly functioning ANS is crucial for maintaining balanced involuntary actions that allow the body to function. Many suffer from dysfunction of this system resulting in a range of symptoms classified as POTS.

While this illness can be complex with various underlying causes, a functional medicine approach can help patients reduce and cope with symptoms such as fluctuations in blood pressure, heart rate, and digestion.