Autonomic neuropathy is damage to the nerves that run the body's automatic functions: heart rate, blood pressure, digestion, bladder emptying, sweating, pupil responses and sexual function. It usually occurs as part of a wider peripheral neuropathy.
Diabetes is by far the commonest cause. Symptoms are often put down to other things for years. Established nerve damage rarely reverses, but treating the cause can stop progression, and most symptoms can be eased with a combination of practical measures and medicines.
Symptoms
- Light-headedness, blurred vision or fainting on standing (orthostatic hypotension)
- A fast resting pulse, or poor tolerance of exercise
- Early fullness, bloating, nausea and vomiting of undigested food (gastroparesis)
- Constipation, or diarrhoea that is worse at night
- Difficulty emptying the bladder, a weak stream, overflow leakage or recurrent infections
- Erectile dysfunction, or vaginal dryness
- Reduced sweating in the feet, excessive sweating of the upper body or while eating
- Not noticing the warning signs of low blood sugar
- Trouble adjusting vision between light and dark
Causes and risk factors
Long-standing or poorly controlled diabetes accounts for most cases. Other causes include amyloidosis (hereditary transthyretin and light chain types), autoimmune conditions such as Sjogren's syndrome, autoimmune autonomic ganglionopathy, Guillain-Barre syndrome, cancer-related (paraneoplastic) syndromes, excess alcohol, vitamin B12 deficiency, chemotherapy drugs such as vincristine and platinum agents, HIV, and rare hereditary neuropathies. Parkinson's disease and multiple system atrophy produce autonomic failure from within the brain and need distinguishing from a nerve disorder.
How it is diagnosed
- Lying and standing blood pressure: A sustained fall of 20 systolic or 10 diastolic within 3 minutes of standing defines orthostatic hypotension.
- Cardiovascular autonomic reflex tests: Heart rate response to deep breathing, the Valsalva manoeuvre and standing.
- Sudomotor testing: QSART or a thermoregulatory sweat test measures small fibre function.
- Gastric emptying scintigraphy: Confirms gastroparesis after endoscopy has excluded a blockage.
- Bladder scan and urodynamics: Measure residual urine and bladder muscle function.
- Blood tests for the cause: HbA1c, B12, protein electrophoresis with free light chains, autoimmune and ganglionic antibodies, transthyretin gene testing.
- Skin biopsy: Counts small nerve fibres when standard nerve conduction tests are normal.
Treatment options
- Treating the cause: Good glucose control, B12 replacement, stopping alcohol, immunotherapy for autoimmune forms, and gene-silencing or stabiliser drugs for transthyretin amyloidosis.
- Non-drug measures for low blood pressure: Rising slowly, extra fluids and salt if your heart allows, compression stockings or an abdominal binder, raising the head of the bed, and reviewing blood pressure tablets.
- Medicines for orthostatic hypotension: Midodrine, fludrocortisone or droxidopa, with care to avoid high blood pressure when lying down.
- Gastroparesis treatment: Small, low fat, low fibre meals; metoclopramide or domperidone in short courses; gastric electrical stimulation or pyloric procedures in selected severe cases.
- Bladder management: Timed voiding, clean intermittent self-catheterisation and medicines as needed.
- Sexual dysfunction: PDE5 inhibitors, vacuum devices, injections or implants for men; lubricants and topical oestrogen for women.
- Sweating and bowel symptoms: Topical glycopyrronium for gustatory sweating; laxatives or loperamide, and antibiotics for bacterial overgrowth.
When it is urgent
Get emergency help locally for fainting with injury, chest pain, a very slow or irregular pulse, inability to pass urine, persistent vomiting with dehydration, or severe low blood sugar without warning. People with cardiac autonomic neuropathy should tell anaesthetists before any operation.
Travelling to Türkiye for treatment
A short visit suits the diagnostic side well: a full autonomic laboratory assessment, a search for the cause including amyloid and autoimmune tests, and a written management plan can be completed in 3 to 5 days. Management itself means adjusting medicines gradually over months against your home blood pressure readings, so you need a doctor nearby who will take the plan forward. If you faint easily, drink plenty, wear compression stockings and book an aisle seat when flying.
Send your reports, scans and a short history and a Clinic-Y coordinator replies within 24 hours with suitable teams and written, all-inclusive proposals side by side. Reviewing your case is free.
الأسئلة المتكررة
Can the nerves recover?
Partial recovery occurs when the cause is removed early, as with B12 deficiency, some autoimmune forms and well controlled early diabetes. Long-standing damage is usually permanent but symptoms can still be controlled.
Is it the same as POTS?
No. POTS is a fast heart rate on standing without a drop in blood pressure. It can overlap with small fibre neuropathy but is a different diagnosis.
Is it dangerous?
Cardiac autonomic neuropathy raises the risk of rhythm disturbance and silent heart disease, so cardiovascular risk factors deserve strict attention.
Why do I feel worse after meals or in heat?
Blood pools in the gut after eating and in the skin when hot, lowering blood pressure further. Smaller meals and avoiding hot baths help.