Yes, POTS (postural orthostatic tachycardia syndrome) is a disorder of the autonomic nervous system. It falls under the umbrella of dysautonomia, a group of conditions in which the autonomic nervous system fails to regulate basic body functions properly. In POTS, the specific malfunction involves how your body adjusts heart rate and blood flow when you stand up, but the effects ripple out to digestion, sweating, concentration, and energy levels.
What the Autonomic Nervous System Does
Your autonomic nervous system controls everything your body handles without conscious effort: heart rate, blood pressure, digestion, temperature regulation, and bladder function. It has two branches. The sympathetic branch speeds things up (your “fight or flight” response), and the parasympathetic branch slows them down (rest and recovery). These two systems constantly balance each other to keep your body stable.
When you stand, gravity pulls blood toward your legs. A healthy autonomic nervous system responds instantly by tightening blood vessels and slightly increasing heart rate to push blood back up toward your brain and organs. In POTS, that response is disrupted. The result is an excessive heart rate increase, typically 30 or more beats per minute within 10 minutes of standing (or 40 beats per minute in adolescents), without a corresponding drop in blood pressure. This threshold is the standard diagnostic criterion.
Why POTS Causes So Many Different Symptoms
Because the autonomic nervous system touches nearly every organ, POTS produces symptoms that seem unrelated at first glance. The hallmark is lightheadedness or near-fainting when upright, but the full picture often includes severe fatigue, brain fog (trouble focusing, remembering, or paying attention), heart palpitations, nausea and vomiting, headaches, excessive sweating, shakiness, and exercise intolerance. Some people notice a pale face or purple discoloration in their hands and feet when their limbs hang below heart level, caused by blood pooling in the extremities.
These symptoms vary widely from person to person. Some people have mild episodes; others find POTS debilitating enough to interfere with work, school, and basic daily activities. The multi-system nature of the symptoms is what often delays diagnosis, since individual complaints may be attributed to anxiety, deconditioning, or other conditions before someone connects them to autonomic dysfunction.
Three Subtypes of POTS
Not everyone with POTS has the same underlying problem. The condition is generally grouped into three subtypes based on what’s going wrong in the autonomic system.
Neuropathic POTS involves damage to small nerve fibers, specifically the ones lining blood vessels. These nerves normally signal blood vessels to tighten when needed. When they break down, vessels in the legs and abdomen can’t constrict properly, so blood pools in the lower body instead of returning to the heart.
Hyperadrenergic POTS stems from an overactive sympathetic nervous system. The body releases too much norepinephrine (the main chemical messenger of the fight-or-flight response), driving up heart rate and sometimes blood pressure. People with this subtype often experience pronounced anxiety, tremors, and a sense of being “wired.”
Hypovolemic POTS is tied to abnormally low blood volume. Less blood circulating means less blood returning to the heart when you stand, which forces the heart to compensate by beating faster. This subtype sometimes develops after illness, injury, or any event causing significant fluid loss.
These categories overlap. Many people have features of more than one subtype, which is part of why treatment needs to be tailored individually.
Conditions That Can Trigger Secondary POTS
POTS can appear on its own (primary) or develop as a consequence of another disease (secondary). Chronic diabetes is the most common condition linked to secondary POTS, because long-term high blood sugar damages the small nerve fibers that regulate blood vessels. Other associated conditions include lupus, Sjögren’s syndrome, amyloidosis, sarcoidosis, and heavy metal exposure. Certain chemotherapy drugs can also trigger it. In recent years, a notable number of cases have emerged after viral infections, including COVID-19.
When POTS is secondary, treating the underlying condition sometimes improves autonomic symptoms. When it’s primary, management focuses directly on reducing the heart rate response and expanding blood volume.
How POTS Is Diagnosed
Diagnosis typically involves a tilt table test or an active standing test. You lie flat while your heart rate and blood pressure are monitored, then either stand or are tilted upright to about 70 degrees. If your heart rate jumps by 30 beats per minute or more (40 in teens) within 10 minutes, without a major blood pressure drop, and you have symptoms that have lasted at least three months, the criteria for POTS are met. Additional testing sometimes includes blood volume measurement, autonomic reflex screening, or small fiber nerve biopsy to identify the subtype.
Lifestyle Changes That Help
The first line of management is not medication. Fluid and salt intake are central. Guidelines from the University of Calgary recommend drinking about 3 liters of water daily and consuming 10 to 12 grams of salt per day (roughly two teaspoons of table salt, which provides 4 to 5 grams of sodium). This is dramatically more salt than typical dietary advice, and it works by expanding blood volume so less pooling occurs when you stand.
Exercise is equally important but requires a specific approach. Because standing exercise can trigger symptoms, people with POTS are advised to start with recumbent (non-upright) activities like rowing, recumbent cycling, or swimming for about 30 minutes at least four times per week. Leg strengthening exercises are added separately, since building thigh muscle mass helps squeeze blood back toward the heart during standing. These exercise programs are typically graduated over several months, and many people see meaningful improvement.
Medication Options by Subtype
When lifestyle measures aren’t enough, medications target the specific autonomic dysfunction at play. For people whose main problem is a racing heart, beta blockers reduce heart rate by blocking the effects of norepinephrine. A placebo-controlled trial at Vanderbilt’s Autonomic Dysfunction Center showed that propranolol decreased standing heart rate and acutely improved symptoms.
For low blood volume, fludrocortisone helps the kidneys retain sodium and water, expanding plasma volume. Desmopressin works differently, reducing urine output to achieve the same goal. For blood pooling in the legs, midodrine constricts blood vessels and reduces the amount of blood that settles in the extremities.
Hyperadrenergic POTS, where the sympathetic nervous system is in overdrive, sometimes responds to central sympatholytics like guanfacine or methyldopa, which act on the brain to dial down sympathetic output. Another option, pyridostigmine, works by boosting levels of a neurotransmitter involved in autonomic signaling. It reduced standing heart rate and improved symptoms in a separate placebo-controlled trial.
Most people with POTS use a combination of lifestyle changes and one or two medications, adjusted over time as symptoms shift. The condition is not always permanent. Some people, particularly those who developed POTS after a viral illness or during adolescence, see significant improvement or full resolution within a few years.