This story is not about POTs for cooking; it is about a life-altering disorder called POTS, one that researchers are still trying to understand. The full name of the condition is “postural orthostatic tachycardia syndrome,” also known as “postural anatomic tachycardia.” The primary symptom of this condition is an extremely rapid heart rate (tachycardia) when someone transitions from a laying position to a sitting or standing one, which can cause lightheadedness and fainting. Additional debilitating POTS symptoms can include brain fog, severe fatigue, profound weakness with standing, racing heart, intolerance to exertion, and muscle aches.

The condition affects anywhere from one to three million Americans. Identification of the primary cause of the disorder is difficult and still being studied. Regardless, the condition can be managed, but only if it is diagnosed correctly.

ALTERED AUTOMATIC FUNCTIONS

POTS is the result of altered functioning of the body’s “autonomic nervous system.” I substitute the word “automatic” for the word “autonomic” when explaining this system to my patients. You see, the autonomic nervous system regulates functions such as breathing, heartbeat, and digestion based on the current needs of the system.

For example, when you run up a flight of steps, the autonomic nervous system will upregulate or increase your heart rate and respiratory rates in order to serve the muscle tissue with a sufficient blood and oxygen supply. Another example would be when you are startled or scared. Your heart and pulse rates will increase, your pupils will dilate, and your digestive system will slow or shut down. This all occurs without you giving any conscious thought to the process.

This component of the nervous system is divided into two subunits. One is called the “sympathetic division.” The other is known as the “parasympathetic division.”

Think of the sympathetic division as the gas pedal in your car; it speeds things up. Alternately, the parasympathetic division would be the brake pedal; it slows things down. These two subunits of the autonomic nervous system work in concert to balance each other out. The sympathetic system speeds things up and the parasympathetic system slows things down when it is necessary and appropriate.

So as an example, when you go to sleep, the parasympathetic system should take over. It comes into dominance over the sympathetic division. Conversely, when you wake up in the morning the sympathetic component should come into dominance and get you up and moving.

Unfortunately, in those suffering from POTS, there is a malfunction and an overreaction so to speak.

VARIOUS TYPES OF POTS

There are actually two main forms of POTS along with several subtypes of both.

POTS will be either a primary form or a secondary form. The primary type of POTS has no known cause for it. The secondary form may potentially be due to an “autonomic neuropathy,” which is a fancy way to say there is some form of a breakdown of the function of the autonomic nervous system.

Researchers have found compelling evidence of an association between diabetes, Lyme disease, and other infections and chronic autoimmune dysfunctions.

Primary POTS has additional subtypes, which include the following:

Neuropathic POTS: This form causes blood to pool in the legs due to poor signaling of the small nerve fibers to the blood vessels in the abdomen and legs, which causes them to constrict and slow the blood flow.

Partial Dysautonomic POTS: With this type of POTS, there is partial damage to the nerves that control such things as heart rate and peripheral blood vessels, which makes it difficult to regulate blood pressure. This too can cause the pooling of blood in the lower extremities.

Hyperadrenergic POTS: This derivation of POTS causes an elevation of the adrenal stress hormone norepinephrine. This overstimulation of the sympathetic nervous system causes all of the normal stress responses to occur without any conscious input from you. So, your heart rate will increase, blood pressure will elevate, and blood vessel walls will constrict. Statistically 30-50% of POTS patients have this form. There can be genetic and pharmaceutical causes of these changes as well. Therefore, these causes must be ruled out in making a diagnosis of the condition.

Hypovolemic POTS: This subgroup of POTS is caused by a low blood volume and therefore is also know as “low blood volume POTS.” It has been reported that up to 70% of those suffering from POTS have a lower-than-normal blood volume. The typical blood volume in humans is approximately 5 liters. In this form of POTS, the “fluid regulating system” of the body involving the kidneys and specific hormones can be the root of the problem.

POTS DIAGNOSIS

As with any “syndrome,” the diagnosis is made by assessing the collection of symptoms that appear together. In other words, there is not a specific cause as you can see from what we just reviewed. There may be multiple causes. POTS is not a specific disease entity; there are other things triggering it. Determining the specific cause or causes can be challenging.

Oftentimes if the cause(s) cannot be determined, the condition is relegated to a psychological issue such as anxiety, which ironically can be a symptom of POTS. In these instances, the condition may be labeled “primary” or “idiopathic” POTS.

In my next installment of this article, I will review the potential causes, complications, and treatments for POTS.