When most people picture neuropathy, they picture burning feet. Tingling hands. Numbness that creeps up from the toes. These are real and common symptoms, but they represent only one type of nerve damage: damage to the sensory and motor fibers that carry signals between your brain and your limbs.

There is another type that gets far less attention, affects far more systems in the body, and sends patients on years-long journeys through specialists who never quite connect the dots.

It is called autonomic neuropathy, and it may be one of the most underdiagnosed conditions in conventional medicine.

What the Autonomic Nervous System Actually Does

Your autonomic nervous system is the part of your nervous system that runs in the background. You do not consciously tell your heart to beat, your stomach to digest, your blood vessels to constrict when you stand up, or your sweat glands to respond to heat. The ANS handles all of it automatically.

It operates through two branches: the sympathetic system, which activates your body under stress or demand, and the parasympathetic system, which governs rest, recovery, and digestion. These two branches are meant to work in balance, with each modulating the other depending on what your body needs at any given moment.

When the nerves that make up the autonomic nervous system are damaged, that balance breaks down. And because the ANS touches virtually every organ system in the body, the downstream effects can look completely different from one patient to the next.

What Autonomic Neuropathy Looks Like

This is part of why autonomic neuropathy is missed so often. The symptoms do not always fit neatly into a single specialty, and they frequently do not look like what most people associate with nerve damage.

Common presentations include:

Heart rate and blood pressure irregularities. One of the most recognized forms of autonomic dysfunction is orthostatic hypotension, where blood pressure drops significantly when standing, causing dizziness, lightheadedness, or fainting. Related to this is POTS, or Postural Orthostatic Tachycardia Syndrome, in which the heart rate spikes abnormally upon standing because the autonomic system is not properly regulating cardiovascular response. Patients with these symptoms are often told they are dehydrated, anxious, or simply need to increase their salt intake without anyone investigating the underlying nerve dysfunction.

Digestive dysfunction. The vagus nerve, which plays a central role in parasympathetic function, is a major driver of digestive activity. When autonomic nerve damage affects this pathway, patients can develop gastroparesis, chronic nausea, bloating, constipation, or diarrhea that does not respond to dietary changes. These patients frequently cycle through gastroenterology without resolution because the root issue is neurological, not gastrointestinal.

Abnormal sweating. Autonomic neuropathy can cause excessive sweating, reduced or absent sweating, or sweating that occurs in unusual patterns. Patients who report that they can no longer sweat normally during exercise, or who sweat heavily at rest, are often dismissed or given a diagnosis that does not address the nerve component.

Bladder dysfunction. The nerves that regulate bladder contraction and relaxation are part of the autonomic network. Damage here can cause urinary retention, urgency, or incontinence, symptoms that often send patients to urology rather than neurology.

Sexual dysfunction. Autonomic nerve damage can impair the nerve signals required for normal sexual response in both men and women. This is a recognized complication of diabetic neuropathy in particular, though it is rarely discussed directly with patients.

Temperature dysregulation. Difficulty tolerating heat or cold, or an inability to maintain consistent body temperature, can reflect autonomic dysfunction affecting the body’s thermoregulatory system.

Why It Gets Missed

The single biggest reason autonomic neuropathy goes undiagnosed for so long is that the symptoms rarely present together in an obvious way. A patient with digestive issues goes to a GI specialist. A patient with heart rate spikes goes to a cardiologist. A patient with bladder problems goes to a urologist. Each provider evaluates their system in isolation and, finding no structural damage within their specialty, sends the patient home with a partial answer or no answer at all.

Standard nerve conduction studies, which are the most commonly ordered neurological test for neuropathy, primarily assess large sensory and motor fibers. They do not evaluate autonomic fiber function. A patient with significant autonomic neuropathy can have completely normal nerve conduction results, which leads to the conclusion that nothing is wrong neurologically, when in fact the autonomic fibers are substantially compromised.

This is not a failure of individual providers. It is a structural gap in how conventional medicine is organized. When care is siloed by organ system and the most commonly ordered tests are not designed to detect autonomic dysfunction, patients fall through the cracks.

How Autonomic Neuropathy Is Evaluated at Nexus Neuro

At Nexus Neuro in Carmel, Indiana, autonomic function is a core component of how we evaluate every neuropathy patient. The nervous system does not operate in separate departments, and neither does our diagnostic process.

We use Nerve Express ANS testing to directly measure how the autonomic nervous system is functioning. This technology evaluates heart rate variability and autonomic balance, providing objective data on sympathetic and parasympathetic activity that cannot be captured through standard neurological exams or imaging. It allows us to see whether the two branches of the ANS are communicating properly, whether one is chronically dominant, and how the system responds under different conditions.

This matters because treatment that is right for a patient with primarily sensory neuropathy may be entirely different from what is appropriate for a patient whose autonomic system is dysregulated. Understanding what is actually happening in the nervous system is the only way to build a care plan that addresses the real problem.

For patients whose autonomic dysfunction has a significant cardiovascular component, such as those presenting with POTS or orthostatic symptoms, we also look at the broader picture of what is driving the dysregulation. Metabolic contributors, inflammatory processes, gut-brain axis dysfunction, and nutritional deficiencies all have documented effects on autonomic nerve health. Addressing those upstream factors is part of what makes a functional neurology approach different from a specialty that evaluates only one system at a time.

What This Means if You Have Been Told Your Tests Are Normal

If you have been living with unexplained digestive symptoms, heart rate irregularities, dizziness upon standing, or any combination of the symptoms described above, and you have been told your tests look fine, it is worth considering whether autonomic nerve function has actually been assessed.

Normal imaging does not rule out autonomic neuropathy. Normal nerve conduction studies do not rule out autonomic neuropathy. These tests are simply not designed to measure what the autonomic nervous system is doing.

At Nexus Neuro, we work with patients across the Indianapolis metro area, including Carmel, Westfield, Fishers, Zionsville, and Noblesville, who have spent years being told nothing is wrong. In many cases, a thorough autonomic evaluation reveals dysfunction that has been present and progressing the entire time.

If your symptoms do not have a clear explanation, the answer may not be that nothing is wrong. The answer may be that the right questions have not been asked yet.

To schedule a consultation at Nexus Neuro, call 317-884-8824 or visit nexusneurohealth.com.