Symptoms and causes
Autonomic neuropathy
The nerves that run your blood pressure, your gut, your bladder and your sweat glands can be damaged by exactly the same processes that damage the nerves in your feet — and almost nobody thinks to connect the two.
Written by the Managing Neuropathy editorial team under the direction of Dr. Tom Biernacki, DPM, FACFAS · Clinical review pending · Last updated 7 September 2026
The short answer. Autonomic neuropathy is damage to the nerves that control automatic functions. The fibers involved are small and unmyelinated — the same class that produces burning feet — so it commonly travels with, and is hidden by, an ordinary painful neuropathy. Its symptoms get attributed to age, medication or anxiety for years. The cardiovascular form is the one with the most serious long-term implications, and the sweating form is the one that quietly turns a numb foot into an ulcer.
What these nerves actually do
The autonomic nervous system is the housekeeping department. It raises your heart rate when you stand, narrows blood vessels to keep blood in your head, pushes food along the gut, empties the bladder, opens sweat glands when skin gets dry or hot, and dilates the pupil in a dark room. None of it reaches consciousness — which is precisely why its failure is described in vague terms rather than reported as a symptom.
The symptom list, system by system
| System | What people notice |
|---|---|
| Cardiovascular | Lightheaded or grey vision on standing; a resting pulse that sits high and never varies; breathlessness or fatigue on exertion out of proportion to fitness; fainting |
| Digestive | Feeling full after a few mouthfuls; nausea hours after eating; bloating; constipation alternating with sudden diarrhoea, often at night; unpredictable blood sugars after meals |
| Bladder and sexual | Not knowing the bladder is full; a weak or hesitant stream; incomplete emptying and repeated urinary infections; erectile difficulty; vaginal dryness |
| Sweating | Feet and lower legs that no longer sweat, with dry, shiny, cracking skin; heavy compensatory sweating of the head and trunk; sweating while eating |
| Metabolic | Loss of the shakiness, sweating and pounding heart that used to warn of a low blood sugar |
| Eye | Slow adjustment going from a bright room into a dark one |
The cardiovascular form is the one that matters most
Cardiovascular autonomic neuropathy is the most studied and the most consequential. Three of its features are worth knowing by name.
Orthostatic hypotension. Blood pressure drops when you stand because the reflex that should tighten your vessels no longer fires. It causes lightheadedness, greyed vision, unsteadiness and falls — and in someone whose balance is already impaired by sensory neuropathy, the two problems multiply rather than add.
A resting heart rate that has lost its variability. A healthy heart rate rises and falls with each breath. When the vagus nerve is damaged that variation flattens and the resting rate settles high. It is measurable, and it is one of the earliest signs.
Blunted warning of cardiac events. When the nerves carrying cardiac pain are damaged, a heart attack can present as breathlessness, nausea or nothing at all rather than chest pain. This is also why anaesthetists take a documented autonomic neuropathy seriously before surgery — blood pressure control under anaesthesia is less stable.
The sweating problem, and why a podiatrist cares
This is the part that gets left out of general descriptions, and it is the reason autonomic neuropathy belongs on a foot site.
When the sudomotor fibers to the feet fail, the skin stops sweating. It becomes dry, shiny and inelastic, and it splits — classically at the back of the heel, where a fissure can be deep enough to bleed. Now combine that with the sensory loss that usually accompanies it: a crack in the skin that the person cannot feel, on a foot they may not be able to see easily, in tissue with reduced blood flow. That is a direct route to infection, and it is one of the most preventable problems in the whole of diabetic foot care.
The practical response is unglamorous and effective: a urea-based or thick emollient cream applied daily to the soles and heels but never between the toes, where trapped moisture does the opposite of good; and a genuine daily inspection of the skin. The daily check takes about a minute. Sock choice matters here too, because dry, fragile skin does badly against a seam.
What causes it
- Diabetes — by a wide margin the most common cause, and the risk rises with duration and with glucose variability.
- Autoimmune disease, including Sjögren’s syndrome and autoimmune autonomic ganglionopathy.
- Amyloidosis, both hereditary and acquired, which characteristically hits small and autonomic fibers early.
- Parkinson’s disease and related conditions, where autonomic failure often predates the movement problem.
- Alcohol, in the same dose-related way it damages sensory nerves. More on that here.
- Chemotherapy and some other drugs, and certain infections.
How it is tested
You do not need a specialist laboratory for the most useful test. Lying and standing blood pressure — measured after lying five minutes, then at one and three minutes standing — detects orthostatic hypotension and takes almost no time. Beyond that, heart rate variability with deep breathing and with standing, tilt-table testing, sweat testing such as QSART or a thermoregulatory sweat test, gastric emptying studies and bladder ultrasound for residual volume all exist for specific questions. The point worth making to your own clinician is simply that the blood pressure part should be measured lying and standing, because a single seated reading cannot show it.
What helps
Glucose control, alcohol reduction and treatment of an underlying autoimmune or infiltrative disease are the only measures that address the nerve damage itself. The treatment hierarchy is here.
Blood pressure tablets, diuretics, some antidepressants and prostate medicines all worsen a postural drop. Timing and dose changes often help more than adding anything new.
Sit on the edge of the bed, pump the ankles, then stand. Raising the head of the bed slightly overnight helps some people.
Both are commonly advised for orthostatic hypotension and both are unsuitable for some people with heart or kidney disease, which is why this is a conversation and not a self-prescription.
Abdominal binders and waist-high garments target where the blood actually pools. Note that compression is not automatically safe — it is contraindicated in significant peripheral arterial disease. The compression question is covered in full here.
Delayed emptying also shifts when insulin should be given, which is a discussion to have rather than an adjustment to guess at.
Daily emollient, daily inspection, never barefoot, and shoes checked before they go on.
When to be seen promptly
Fainting rather than lightheadedness. Falls. Chest discomfort, breathlessness or unexplained sweating in anyone with diabetes and known neuropathy, because a blunted warning system makes an atypical presentation more likely. Repeated vomiting or an inability to keep food down. Being unable to pass urine. Losing the ability to sense low blood sugars, which needs a change of plan with your diabetes team rather than watchful waiting.
Common questions
Can I have autonomic neuropathy without burning or numb feet?
Yes, though it is less common. Some conditions — amyloidosis, certain autoimmune forms, Parkinson’s disease — affect autonomic fibers disproportionately. More often it accompanies a small-fiber neuropathy, and the loud foot symptoms mask the quiet systemic ones.
Is it reversible?
The realistic goal is to stop it progressing and to manage the consequences well. Where a specific reversible driver exists — alcohol, a nutritional deficiency, a treatable autoimmune process, poor glucose control — addressing it can improve matters. General regeneration claims are not supported. Why those claims persist is worth reading.
Why am I dizzy standing but my blood pressure is fine at the surgery?
Because a seated reading cannot detect a postural drop. It has to be measured lying, then standing at one and three minutes. Ask for it that way.
My feet are dry and cracked but I moisturize every day. Why?
Check where it is going and what it is. Emollient on the soles and heels, not between the toes, and a urea-containing preparation for thickened dry skin. If deep fissures persist despite that, they need looking at rather than more cream — a heel fissure in a numb foot is an entry point for infection.
Does this change anything before surgery?
It can. Documented cardiovascular autonomic neuropathy is relevant to anaesthetic planning because blood pressure is less stable. It is worth mentioning explicitly at a pre-operative assessment rather than assuming it is in the notes.
Related reading
The full symptom list · Diabetic neuropathy · Small fiber neuropathy · Types of neuropathy · The daily foot check · Treatment, in full
Sources and further reading: American Diabetes Association Standards of Care, section on diabetic neuropathy including cardiovascular autonomic neuropathy. Published consensus statements on the diagnosis and staging of diabetic autonomic neuropathy. Reviews of orthostatic hypotension management and of gastroparesis in diabetes. National Institute of Neurological Disorders and Stroke, autonomic neuropathy information.
This page is general education and is not a diagnosis or a treatment plan. Clinical review by Dr. Biernacki is pending; the review date will be shown here once complete.
For our Michigan neighbors
Dry, cracking feet are
a nerve finding.
Skin that has stopped sweating on a foot that has stopped feeling is a combination worth taking seriously before it splits. Dr. Biernacki’s Michigan practice assesses and protects those feet.
Everywhere else, take this page to your own clinician.
Dr. Tom Biernacki, DPM, FACFAS is a double board-certified foot and ankle surgeon (ABFAS and ABPM) and a Fellow of the American College of Foot & Ankle Surgeons. He is the founder of Balance Foot & Ankle in Howell and Bloomfield Township, Michigan, where peripheral neuropathy, diabetic foot risk and loss of protective sensation are part of his weekly clinic. His patient education videos have drawn more than 950,000 subscribers on YouTube. He writes Managing Neuropathy to put the explanation he gives in the exam room in front of the people who cannot get to one — including when a product is worth buying and when it is not.