Autonomic neuropathy

Overview

Autonomic neuropathy occurs when there is damage to the nerves that control automatic body functions. It can affect blood pressure, temperature control, digestion, bladder function and even sexual function.

The nerve damage affects the messages sent between the brain and other organs and areas of the autonomic nervous system. These areas include the heart, blood vessels and sweat glands.

Diabetes is the most common cause of autonomic neuropathy. It can also be caused by other health conditions, viral or bacterial infections, or some medications. Symptoms and treatment vary based on which nerves are damaged.

Symptoms

Signs and symptoms of autonomic neuropathy depend on which nerves are damaged. They might include:

Dizziness and fainting when standing, caused by a sudden drop in blood pressure.
Urinary problems, such as difficulty starting urination, loss of bladder control, difficulty sensing a full bladder and inability to completely empty the bladder. Not being able to completely empty the bladder can lead to urinary tract infections.
Sexual difficulties, including problems achieving or maintaining an erection (erectile dysfunction) or ejaculation problems. In women, problems include vaginal dryness, low libido and difficulty reaching orgasm.
Difficulty digesting food, such as feeling full after a few bites of food, loss of appetite, diarrhea, constipation, abdominal bloating, nausea, vomiting, difficulty swallowing and heartburn. These problems are all due to changes in digestive function.
Inability to recognize low blood sugar (hypoglycemia), because the warning signals, such as getting shaky, aren't there.
Sweating problems, such as sweating too much or too little. These problems affect the ability to regulate body temperature.
Sluggish pupil reaction, making it difficult to adjust from light to dark and seeing well when driving at night.
Exercise intolerance, which can occur if your heart rate stays the same instead of adjusting to your activity level.

When to see a doctor

Seek medical care promptly if you begin having any of the signs and symptoms of autonomic neuropathy, particularly if you have diabetes that's poorly controlled.

If you have type 2 diabetes, the American Diabetes Association recommends annual autonomic neuropathy screening beginning when you receive your diagnosis. For people with type 1 diabetes, the association advises annual screening beginning five years after diagnosis.

Causes

Many health conditions can cause autonomic neuropathy. It can also be a side effect of treatments for other diseases, such as cancer. Some common causes of autonomic neuropathy include:

Diabetes, especially when poorly controlled, is the most common cause of autonomic neuropathy. Diabetes can gradually cause nerve damage throughout the body.
Irregular protein buildup in organs (amyloidosis), which affects the organs and the nervous system.
Autoimmune diseases, in which your immune system attacks and damages parts of your body, including your nerves. Examples include Sjogren syndrome, systemic lupus erythematosus, rheumatoid arthritis and celiac disease. Guillain-Barre syndrome is an autoimmune disease that happens rapidly and can affect autonomic nerves.

Autonomic neuropathy may also be caused by an immune system attack triggered by some cancers (paraneoplastic syndrome).
Certain medications, including some drugs used in cancer treatment (chemotherapy).
Some viruses and bacteria, such as HIV and those that cause botulism and Lyme disease.
Certain inherited disorders also can cause autonomic neuropathy.

Risk factors

Factors that might increase your risk of autonomic neuropathy include:

Diabetes. Diabetes, especially when poorly controlled, increases your risk of autonomic neuropathy and other nerve damage. You're at greatest risk if you have difficulty controlling your blood sugar.
Other diseases. Some health conditions including amyloidosis, porphyria and hypothyroidism can increase the risk of autonomic neuropathy. Cancer can too, usually due to side effects from treatment.

Prevention

Certain inherited diseases that put you at risk of developing autonomic neuropathy can't be prevented. But you can slow the onset or progression of symptoms by taking care of your health in general and managing your medical conditions.

To control diseases and conditions, follow your health care provider's advice on healthy living. That advice might include these recommendations:

Control your blood sugar if you have diabetes.
Avoid alcohol and smoking.
Get appropriate treatment if you have an autoimmune disease.
Take steps to prevent or control high blood pressure.
Achieve and maintain a healthy weight.
Exercise regularly.

Diagnosis

Autonomic neuropathy is a possible complication of some diseases. The tests you'll need depend on your symptoms and risk factors for autonomic neuropathy.

When you have known risk factors for autonomic neuropathy

If you have diabetes or another condition that increases your risk of autonomic neuropathy and have symptoms of neuropathy, your health care provider will perform a physical exam and ask about your symptoms.

If you are undergoing cancer treatment with a drug known to cause nerve damage, your provider will check for signs of neuropathy.

When you don't have risk factors for autonomic neuropathy

If you have symptoms of autonomic neuropathy but no risk factors, the diagnosis can be more involved. Your health care provider will probably review your medical history, discuss your symptoms and do a physical exam.

Your provider might recommend tests to evaluate autonomic functions, including:

Autonomic function tests. These tests measure how your heart rate and blood pressure respond during exercises such as deep breathing and forcefully breathing out (Valsalva maneuver).
Tilt-table test. This test monitors the response of blood pressure and heart rate to changes in posture and position. It simulates what occurs when you stand up after lying down. You lie flat on a table, which is then tilted to raise the upper part of your body. Typically, blood vessels narrow and heart rate increases to compensate for the drop in blood pressure. This response may be slowed if you have autonomic neuropathy.

A simpler test for this response involves checking your blood pressure when lying, sitting and standing after three minutes. Another test involves standing for a minute, then squatting for a minute and then standing again while blood pressure and heart rate are monitored.
Gastrointestinal tests. Gastric-emptying tests are the most common tests to check for digestive issues such as slow digestion and delayed emptying of the stomach (gastroparesis). These tests are usually done by a doctor who specializes in digestive disorders (gastroenterologist).
Quantitative sudomotor axon reflex test. This test checks how the nerves that manage your sweat glands respond to stimulation. A small electrical current passes through capsules placed on your forearm, upper and lower leg, and foot. A computer analyzes the response of your nerves and sweat glands. You might feel warmth or a tingling sensation during the test.
Thermoregulatory sweat test. You're coated with a powder that changes color when you sweat. While you lie in a chamber with a slowly increasing temperature, digital photos document the results as you begin to sweat. Your sweat pattern might help confirm a diagnosis of autonomic neuropathy or suggest other causes for decreased or increased sweating.
Urinalysis and bladder function (urodynamic) tests. If you have bladder or urinary signs and symptoms, a series of urine and bladder tests can evaluate bladder function.
Ultrasound. If you have bladder signs and symptoms, your provider might recommend an ultrasound of your urinary tract. In this test, high-frequency sound waves create an image of the bladder and other parts of the urinary tract.

Treatment

Treatment of autonomic neuropathy includes:

Treating the underlying disease. The first goal of treating autonomic neuropathy is to manage the disease or condition damaging your nerves. If diabetes is causing your nerve damage, you'll need to tightly control blood sugar to prevent damage from progressing. About half of the time, no underlying cause for autonomic neuropathy is found.
Managing specific symptoms. Some treatments can relieve the symptoms of autonomic neuropathy. Treatment is based on what part of your body is most affected by nerve damage.

Digestive (gastrointestinal) symptoms

Your health care provider may recommend:

Diet changes. You might need more dietary fiber and fluids. Fiber supplements, such as Metamucil or Citrucel, also might help. Slowly increase the amount of fiber you get to avoid gas and bloating.
Medication to help your stomach empty. A prescription drug called metoclopramide (Reglan) helps your stomach empty faster by increasing the contractions of the digestive tract. This medication can cause drowsiness and shouldn't be used for longer than 12 weeks.
Medications to ease constipation. Laxatives that you can buy without a prescription can help ease constipation. Ask your health care provider how often you should use a laxative.
Medications to ease diarrhea. Antibiotics can help treat diarrhea by preventing too much bacterial growth in the intestines. Anti-diarrheal medication available without a prescription might be helpful.

Urinary symptoms

Your health care provider may suggest:

Retraining your bladder. Following a schedule of when to drink fluids and when to urinate can help increase your bladder's capacity and retrain your bladder to empty completely at the appropriate times.
Medication to manage bladder symptoms. Your health care provider may prescribe medications that decrease an overactive bladder. Other medications may help empty your bladder.
Urinary assistance (catheterization). A tube is guided through your urethra to empty your bladder.

Sexual dysfunction

For men with erectile dysfunction, health care providers might recommend:

Medications that enable erections. Drugs such as sildenafil (Viagra), vardenafil, tadalafil (Cialis) and avanafil (Stendra) can help you achieve and maintain an erection. Possible side effects include low blood pressure, mild headache, flushing, upset stomach and changes in color vision.

If you have a history of heart disease, arrhythmia, stroke or high blood pressure, use these medications with caution. Also avoid taking these medications if you are taking any type of organic nitrates. Seek immediate medical assistance if you have an erection that lasts longer than four hours.
External vacuum pump. This device helps pull blood into the penis using a hand pump. A tension ring helps keep the blood in place, maintaining the erection for up to 30 minutes.

For women with sexual symptoms, health care providers might recommend:

Vaginal lubricants to decrease dryness and make sexual intercourse more comfortable and enjoyable.
One of a few medications approved for premenopausal women with low sexual desire.

Heart rhythm and blood pressure symptoms

Autonomic neuropathy can cause heart rate and blood pressure problems. Your health care provider might prescribe:

A high-salt, high-fluid diet. If your blood pressure drops when you stand up, a diet that is high in salt and fluid can help maintain your blood pressure. This treatment can cause high blood pressure or swelling of the feet, ankles or legs. So it is generally recommended only for severe cases of blood pressure problems. And this treatment shouldn't be used in people with heart failure.
Compression garments. A binder worn around the waist or thigh-high compression stockings may help improve blood flow.
Medications to raise your blood pressure. If you feel faint or dizzy when you stand up, your health care provider might suggest medications. Fludrocortisone helps your body retain salt, which helps regulate your blood pressure.

Midodrine (Orvaten) and droxidopa (Northera) can help raise blood pressure. But these drugs can cause high blood pressure when you're lying down. Octreotide (Sandostatin) can help raise blood pressure in people with diabetes who have low blood pressure after eating, but it can cause some side effects. Pyridostigmine (Mestinon) may help keep blood pressure stable when standing.
Medication to regulate your heart rate. A class of medications called beta blockers helps regulate your heart rate if it goes too high during physical activity.

Sweating

If you sweat too much, your health care provider might prescribe a medication that decreases sweating. Glycopyrrolate (Cuvposa, Robinul, others) can decrease sweating. Side effects can include diarrhea, dry mouth, urinary retention, blurred vision, changes in heart rate, headache, loss of taste and drowsiness. Glycopyrrolate can also increase the risk of heat-related illness, such as heatstroke, from a reduced ability to sweat.

Self care

Posture changes. Stand up slowly, in stages, to decrease dizziness. Sit with your legs dangling over the side of the bed for a few minutes before getting up. Flex your feet and make fists with your hands for a few seconds before standing up, to increase blood flow.

Once standing, try tensing your leg muscles while crossing one leg over the other a few times to increase blood pressure.
Elevate the bed. If you have low blood pressure, it might help to raise the head of your bed by about 4 inches (10 centimeters). You can do this by placing blocks or risers under the legs at the head of the bed.
Digestion. Eat small, frequent meals to combat digestive problems. Increase fluids and opt for low-fat, high-fiber foods, which can improve digestion.
Diabetes management. Tight blood sugar control can help lessen symptoms and help prevent or delay the onset of new problems.

Alternative medicine

Several alternative medicine treatments might help people with autonomic neuropathy. Talk with your health care provider about any treatments you want to try. This can help make sure that they won't interfere with your medical treatments or be harmful.

Alpha-lipoic acid

Research suggests this antioxidant might improve the measures of autonomic nerve function. More study is needed.

Acupuncture

This therapy involves placing thin needles in specific points in the body. It might help treat slow stomach emptying and erectile dysfunction. More studies are needed.

Transcutaneous electrical nerve stimulation

This therapy sends low-energy electrical waves through electrodes placed on the skin. Some studies have found that it might help ease pain associated with diabetic neuropathy.

Coping and support

Living with a chronic condition presents daily challenges. Here are some suggestions to help you cope:

Set priorities. Accomplish the most important tasks, such as paying bills or grocery shopping, when you have the most energy. Save less important tasks for later. Stay active, but don't overdo.
Seek and accept help from friends and family. Having a support system and a positive attitude can help you cope with your challenges. Ask for what you need. Don't shut yourself off from loved ones.
Talk to a counselor or therapist. Depression is a possible complication of autonomic neuropathy. Seek help from a counselor or therapist in addition to your primary care provider to discuss possible treatments.
Consider joining a support group. Ask your care provider about support groups in your area. If there isn't a local group for people with neuropathies, you might find a support group for your underlying condition, such as diabetes, or an online support group.

Preparing for your appointment

First, you'll probably see your primary care provider. If you have diabetes, you might see your diabetes doctor (endocrinologist). However, you might be referred to a doctor specializing in nerve disorders (neurologist).

You might see other specialists, depending on the part of your body affected by neuropathy, such as a cardiologist for blood pressure or heart rate problems or a gastroenterologist for digestive difficulties.

Here are some tips to help you prepare for your appointment.

What you can do

Ask if you should do anything before your appointment, such as fasting before certain tests. Make a list of:

Your symptoms, and when they began
All medications, vitamins or other supplements you take, including doses
Questions to ask your health care provider

Take a friend or family member with you to help you remember the information you receive and to learn how to support you. For example, if you pass out from low blood pressure, people around you need to know what to do.

Questions to ask your health care provider about autonomic neuropathy include:

Why did I develop autonomic neuropathy?
Could anything else cause my symptoms?
What tests do I need?
What treatments are available?
Are there alternatives to the treatment you're suggesting?
Is there anything I can do to help manage autonomic neuropathy?
I have other health conditions. How can I best manage those with autonomic neuropathy?
Do I need to follow a special diet?
Are there activities I need to restrict?
Do you have printed materials I can have? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

Your health care provider is likely to ask you questions, such as:

Have your symptoms been continuous or occasional?
How severe are your symptoms?
Does anything seem to improve your symptoms?
What, if anything, appears to worsen your symptoms?