Autonomic neuropathy
Autonomic neuropathy
Definition
Autonomic neuropathy is a type of peripheral neuropathy that affects involuntary body functions, including heart rate, blood pressure, perspiration, digestion and other processes. Instead of a specific disease, autonomic neuropathy refers to damage to the autonomic nerves that results in a variety of signs and symptoms. This damage disrupts signals between the brain and portions of the autonomic system such as the heart, blood vessels and sweat glands, resulting in decreased or abnormal performance of one or more involuntary body functions.
Autonomic neuropathy can be a complication of several diseases and conditions. Some medications cause autonomic neuropathy as a side effect, as well. Signs, symptoms and treatment vary widely depending on the cause, and on which nerves are affected.
Symptoms
Signs and symptoms of autonomic neuropathy vary widely, depending on which parts of your autonomic nervous system are affected. They may include:
Dizziness and fainting upon standing (orthostatic hypotension), caused by a drop in blood pressure
Urinary problems, including difficulty starting urination, overflow incontinence and inability to empty your bladder completely, which can lead to urinary tract infections
Sexual difficulties, including erectile dysfunction or ejaculation problems in men, and vaginal dryness and difficulties with arousal and orgasm in women
Difficulty digesting food (gastroparesis), which can cause a feeling of fullness after eating little, loss of appetite, diarrhea, constipation, abdominal bloating, nausea, vomiting and heartburn
Sweating abnormalities, especially decreased sweating, so the body can't regulate its temperature; also excessive sweating, sometimes after eating
Sluggish pupil reaction, making it difficult to adjust from light to dark and causing difficulties with driving at night
Exercise intolerance, when your heart rate remains unchanged instead of increasing and decreasing in response to your activity level
Lack of usual warning signs of low blood sugar (hypoglycemia), which include shakiness, increased heart rate, sweating and palpitations
Causes
Autonomic neuropathy can be caused by a large number of diseases and conditions or as a side effect of treatment for diseases unrelated to the nervous system. Some common causes of autonomic neuropathy include:
Alcoholism, a chronic, progressive disease that can lead to nerve damage.
Abnormal 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. This includes an abnormal attack by the immune system that occurs as a result of some cancers (paraneoplastic syndromes).
Diabetes, which can gradually cause nerve damage throughout the body.
Multiple system atrophy, a degenerative disorder that leads to loss and malfunction of some portions of the central nervous system.
Injury to nerves caused by surgery or trauma.
Treatment with certain medications, including some drugs used in cancer chemotherapy and anticholinergic drugs, sometimes used to treat irritable bowel syndrome and overactive bladder.
Other chronic illnesses, such as Parkinson's disease and HIV/AIDS.
Risk factors
Having diabetes puts you at high risk of developing nerve damage, including autonomic neuropathy. Risk is greatest for people over 40 who've had the disease for more than 25 years and have difficulty controlling their blood sugar.
Untreated alcoholism, smoking, being overweight, and having high blood pressure or high levels of blood fat also increase your risk of nerve damage.
When to seek medical advice
If you have diabetes, a compromised immune system or another chronic medical condition, see your doctor regularly to be checked for nerve damage. Seek medical care promptly if you begin experiencing any of the signs and symptoms of autonomic neuropathy.
