About Autonomic Neuropathy

What Is Autonomic Neuropathy?

Autonomic neuropathy is nerve damage that affects the autonomic nervous system. This part of the nervous system controls body functions that happen automatically, such as heart rate, blood pressure, digestion, bladder function, sweating, temperature control, pupil response, and sexual function. When these nerves are damaged, the affected organs or body systems may not work normally. Possible problems include:

• Heart rate and blood pressure changes, such as dizziness or feeling faint when standing
• Digestive system issues, including constipation, diarrhea, or delayed stomach emptying
• Bladder problems, such as trouble emptying the bladder or leaking urine
• Sexual function problems
• Abnormal sweating or problems tolerating heat
• Eye problems, such as trouble adjusting to changes in light or seeing well at night
• Reduced ability to notice low blood sugar (hypoglycemia), especially in people with diabetes

Diabetes is one of the most common causes of autonomic neuropathy. Other possible causes include certain infections, autoimmune conditions, neurologic conditions, inherited disorders, alcohol use, some medications, and nerve injury. Symptoms can vary widely depending on which nerves and organs are affected. If you have symptoms that may suggest autonomic neuropathy, talk with a healthcare professional for an accurate diagnosis and appropriate management. Seek urgent medical care for fainting, chest pain, severe dizziness, repeated vomiting, inability to urinate, or repeated episodes of severe low blood sugar.

Autonomic Neuropathy Causes and Risk Factors

Autonomic neuropathy can happen when nerves that control automatic body functions are damaged. Diabetes is one of the most common causes, but it is not the only cause. Risk factors and possible causes include:

• Diabetes, especially when high blood glucose or high triglyceride levels damage nerves and the small blood vessels that supply them
• Longer duration of diabetes or blood glucose levels that are often above target
• Other health conditions, including autoimmune disorders, neurologic conditions such as Parkinson disease or multiple sclerosis, and inherited nerve disorders
• Viral or bacterial infections, such as HIV or Lyme disease
• Spinal cord injury, nerve injury, or surgery that affects autonomic nerves
• Certain medicines or treatments that can damage nerves
• Heavy alcohol use

Some risk factors, such as blood glucose, blood pressure, cholesterol levels, alcohol use, and medication effects, may be managed with help from a healthcare professional. Other causes may not be preventable, but identifying the cause can help guide treatment.

Autonomic Neuropathy Symptoms

Autonomic neuropathy symptoms depend on which nerves and body systems are affected. Symptoms may develop slowly and can vary from person to person.

• Digestive symptoms
  • Constipation, diarrhea, or diarrhea that alternates with constipation
  • Bloating, nausea, heartburn, or trouble swallowing
  • Feeling full after eating only a small amount of food
  • Vomiting undigested food, which may happen with delayed stomach emptying
  • Problems controlling bowel movements
• Bladder symptoms
  • Difficulty starting to urinate
  • Difficulty sensing when the bladder is full
  • Feeling that the bladder does not completely empty after urinating
  • Leaking urine or loss of bladder control
  • Frequent urinary tract infections
• Heart and blood pressure symptoms
  • Dizziness, lightheadedness, or fainting when standing up from sitting or lying down
  • A heart rate that is unusually fast, slow, or does not change as expected with activity
  • Shortness of breath or exercise intolerance with activity
• Other autonomic neuropathy symptoms
  • Reduced ability to notice low blood sugar, especially if warning signs such as shakiness, sweating, or a fast heartbeat are absent
  • Sexual function problems, such as erectile dysfunction, ejaculation problems, vaginal dryness, low libido, or difficulty reaching orgasm
  • Sweating too much or too little, which can affect temperature control
  • Heat intolerance, especially with activity
  • Trouble adjusting from light to dark or seeing well at night

Contact a healthcare professional if you have symptoms that could be related to autonomic neuropathy, especially if you have diabetes or another condition that can affect nerves. Seek urgent medical care for fainting, chest pain, severe dizziness, repeated vomiting, inability to urinate, or repeated episodes of severe low blood sugar.

How Is Autonomic Neuropathy Diagnosed?

To diagnose autonomic neuropathy, a healthcare professional usually reviews symptoms and medical history, performs a physical exam, and chooses tests based on the body systems affected. The evaluation may also look for causes, such as diabetes, medication effects, infections, or other medical conditions. Tests may include:

• A physical exam, including checks of blood pressure, heart rate, reflexes, sensation, and signs of dehydration or bladder problems
• Blood pressure and heart rate measurements while lying down, sitting, and standing
• Autonomic function tests, such as deep-breathing or Valsalva testing, to see how heart rate and blood pressure respond
• A tilt-table test to evaluate dizziness, fainting, or blood pressure changes with posture
• Sweat tests, such as a quantitative sudomotor axon reflex test or thermoregulatory sweat test, to assess sweat gland nerve function
• Gastrointestinal tests, such as a gastric-emptying test, if symptoms suggest delayed stomach emptying or another digestive problem
• Bladder tests, such as urine testing, bladder ultrasound, or urodynamic testing, if symptoms suggest urinary retention, leakage, or recurrent urinary tract infections
• Blood tests or other tests to help identify an underlying cause, such as diabetes, vitamin deficiencies, thyroid disease, infection, or autoimmune disease

Not everyone needs every test. The tests used depend on a person’s symptoms, medical history, risk factors, and exam findings. Follow up with a healthcare professional if symptoms worsen, change, or interfere with daily activities.

Autonomic Neuropathy Treatment Options

Treatment for autonomic neuropathy focuses on treating the underlying cause when possible, slowing further nerve damage, and managing symptoms. The right treatment depends on which body systems are affected and whether autonomic neuropathy is related to diabetes, another medical condition, a medication, alcohol use, or another cause.

Treatment may include:

Treating the underlying cause

• For diabetes-related autonomic neuropathy, managing blood glucose, blood pressure, cholesterol, and triglyceride levels may help slow further nerve damage.
• If a medication, alcohol use, infection, vitamin deficiency, autoimmune condition, or another medical problem may be contributing, a healthcare professional may recommend treatment or changes that address that cause.

Managing symptoms

• Delayed stomach emptying: Eating smaller, more frequent meals and, in some cases, medicines that help the stomach empty more normally
• Constipation or diarrhea: Diet changes, fluids, fiber when appropriate, laxatives, antidiarrheal medicines, or treatments for bacterial overgrowth if recommended
• Bladder symptoms: Timed urination, bladder training, medicines, treatment of urinary tract infections, or catheterization when needed to help empty the bladder
• Sexual function symptoms: Medicines for erectile dysfunction when appropriate, vaginal lubricants or moisturizers, and treatment of contributing factors
• Low blood pressure when standing: Drinking enough fluids if appropriate, rising slowly, compression garments, and medicines that help raise or maintain blood pressure when recommended
• Low blood sugar unawareness: More frequent glucose monitoring, a continuous glucose monitor, and an individualized diabetes plan when recommended

Lifestyle and self-care steps

• Follow a diabetes care plan, if diabetes is the cause or a contributing factor.
• Ask a healthcare professional which diet changes are appropriate for digestive symptoms, because fiber, fat, fluids, and meal size may need to be adjusted based on the symptom.
• Ask before increasing salt or fluids for low blood pressure symptoms, especially if you have heart disease, kidney disease, or high blood pressure.
• Avoid overheating and plan activity carefully if sweating or heat intolerance is a problem.
• Review medicines with a healthcare professional, because some medicines can worsen dizziness, bladder symptoms, constipation, diarrhea, or sexual function problems.

Treatment plans vary depending on the cause, symptoms, medical history, and other medicines a person takes. A healthcare professional can help decide which treatments are appropriate and monitor for side effects.