Yes, POTS (postural orthostatic tachycardia syndrome) is a disorder of the autonomic nervous system. Specifically, it’s classified as a form of dysautonomia, which means the branch of the nervous system that controls involuntary functions like heart rate, blood pressure, sweating, and body temperature isn’t working properly. The result is a heart rate that spikes excessively when you stand up, along with a range of symptoms that can affect daily life.
How the Autonomic Nervous System Is Involved
When a healthy person stands, gravity pulls blood downward into the legs and abdomen. The autonomic nervous system detects this shift almost instantly and sends signals to tighten blood vessels, pushing blood back up toward the brain and heart. In POTS, those blood vessels don’t respond efficiently to the tightening signal. Blood pools in the lower body, less of it reaches the brain, and the nervous system compensates by flooding the body with stress hormones (epinephrine and norepinephrine) to force the heart to beat faster.
That compensatory response is what produces the hallmark rapid heart rate, but also the dizziness, brain fog, palpitations, and fatigue that people with POTS experience. The problem isn’t the heart itself. It’s the nervous system’s failure to coordinate blood flow when your body position changes.
Different Subtypes, Different Nervous System Problems
The underlying nervous system dysfunction in POTS is not the same for everyone. Researchers have identified several distinct mechanisms, which is why POTS is sometimes called a “heterogeneous” condition.
Neuropathic POTS involves actual damage to small nerve fibers that control blood vessel constriction, particularly in the legs and abdomen. Without those nerves functioning properly, blood pools excessively when you stand. In one study of young patients with POTS and neuropathic symptoms, skin biopsies showed abnormal nerve fiber density in 53% of cases. These patients were also three times more likely to have markers of autoimmune activity in their blood, suggesting the nerve damage may stem from an immune system attack on the nerves themselves.
Hyperadrenergic POTS is driven by too much norepinephrine, a chemical messenger the nervous system uses to raise heart rate and tighten blood vessels. Up to 50% of POTS patients have elevated norepinephrine levels when upright. In some cases, this happens because the system that clears norepinephrine from nerve connections isn’t working correctly, leaving too much of it circulating. People with this subtype tend to experience more prominent palpitations, trembling, and anxiety, all signs of an overactive “fight or flight” response.
Other contributing mechanisms include low blood volume, physical deconditioning, and hormonal imbalances. Some patients have inappropriately low levels of the hormones that help the kidneys retain salt and water, making it harder to maintain adequate blood volume. Many people have overlapping mechanisms rather than fitting neatly into one category.
Viral Infections as a Trigger
POTS has gained wider attention since the COVID-19 pandemic because viral infections can trigger autonomic nervous system dysfunction. In a large study published by the American Heart Association, roughly one-third of highly symptomatic long COVID patients met the diagnostic criteria for POTS, compared to an estimated prevalence of just 0.2% to 1% in the general population. Those who developed post-COVID POTS were younger (average age 40) and overwhelmingly female (91%).
The proposed explanation is that in genetically susceptible people, an infection can overstimulate the immune system, leading to damage to the small nerve fibers that regulate blood vessel tone. COVID isn’t unique in this regard. POTS has long been linked to other viral illnesses, including Epstein-Barr virus and influenza, as well as to surgery, pregnancy, and other physiological stressors.
Who Gets POTS
POTS predominantly affects women of reproductive age, though it can occur in men, children, and older adults. The female predominance is striking: across studies, women consistently make up 80% to 90% of diagnosed cases. The reasons for this skew aren’t fully understood, though hormonal influences and differences in vascular structure likely play a role.
How POTS Feels Day to Day
Because POTS is a nervous system disorder rather than a single-organ problem, its symptoms are wide-ranging. Standing in line at a grocery store, taking a hot shower, or simply getting out of bed can trigger a cascade of symptoms: lightheadedness, racing heart, blurred vision, nausea, and mental fogginess. Some people experience trembling, chest discomfort, or exercise intolerance. The severity varies enormously. Some people manage with lifestyle adjustments, while others find the condition disabling.
A key distinction: POTS causes the heart to race upon standing, but blood pressure typically doesn’t drop significantly. This separates it from orthostatic hypotension, where blood pressure itself falls sharply. In POTS, the nervous system is overcompensating with a rapid heart rate precisely because it’s trying (and partly failing) to maintain blood pressure.
Managing POTS Through the Nervous System
Because the root problem is autonomic, treatment focuses on supporting the nervous system’s ability to regulate blood flow rather than on fixing the heart. The first-line approaches are non-pharmacological.
Fluid and salt loading: Most POTS patients are advised to drink about two liters of fluid and consume three to five grams of salt daily (except those with the hyperadrenergic subtype). The extra salt helps the body retain fluid, increasing blood volume so there’s more to circulate when you stand. Five grams of table salt provides roughly 2,000 milligrams of sodium, well above what most dietary guidelines recommend for the general population but therapeutic for POTS.
Structured exercise: A graduated exercise program is one of the most effective long-term strategies. The protocol developed at Children’s Hospital of Philadelphia starts with recumbent exercise only, such as a recumbent bike, rowing machine, or swimming, for the first three months. This avoids triggering symptoms while building cardiovascular fitness. Upright exercise like walking on a treadmill isn’t introduced until month five, and higher-intensity training comes around month six. Lower body and core strengthening is emphasized because leg muscles act as pumps that push blood back toward the heart with every step. The full program spans six to eight months, and the progression matters. Jumping straight to upright exercise often backfires.
Compression garments: Waist-high compression stockings or abdominal binders reduce blood pooling in the legs and abdomen, giving the nervous system less work to do when you stand.
When lifestyle measures aren’t enough, medications target specific nervous system mechanisms. For neuropathic POTS, drugs that enhance blood vessel constriction can help. For hyperadrenergic POTS, medications that dial down the overactive sympathetic nervous system response are sometimes used. The choice depends on which subtype is dominant, which is one reason accurate diagnosis matters.
Why the “Nervous System Disorder” Label Matters
For years, many POTS patients were told their symptoms were caused by anxiety or deconditioning. Understanding POTS as a measurable autonomic nervous system disorder, with identifiable subtypes, nerve fiber abnormalities visible on biopsy, and quantifiable norepinephrine levels, has changed that. It validates what patients experience and directs treatment toward the actual underlying problem. Anxiety can certainly coexist with POTS, and the surge of stress hormones in hyperadrenergic POTS can mimic anxiety symptoms closely. But the two conditions have different origins and require different approaches.