Autonomic neuropathy occurs when the nerves that control involuntary bodily functions are damaged. It can affect blood pressure, temperature control, digestion, bladder function and even sexual function.
The nerve damage interferes with the messages sent between the brain and other organs and areas of the autonomic nervous system, such as the heart, blood vessels and sweat glands.
While diabetes is the most common cause of autonomic neuropathy, other health conditions — even an infection — can be to blame. Some medications also might cause nerve damage. Symptoms and treatment vary based on which nerves are damaged.
Signs and symptoms of autonomic neuropathy depend on the nerves affected. They might include:
- Dizziness and fainting when standing, caused by a sudden drop in blood pressure (orthostatic hypertension).
- Urinary problems, such as difficulty starting urination, incontinence, difficulty sensing a full bladder and inability to completely empty the bladder, which can lead to urinary tract infections.
- Sexual difficulties, including problems achieving or maintaining an erection (erectile dysfunction) or ejaculation problems in men. 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, 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 abnormalities, such as sweating too much or too little, which 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.
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:
- 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. Examples include Sjogren's syndrome, systemic lupus erythematosus, rheumatoid arthritis and celiac disease. Guillain-Barre syndrome is an autoimmune disease that happens rapidly and can affect autonomic nerves.
An abnormal attack by the immune system that occurs as a result of some cancers (paraneoplastic syndrome) can also cause autonomic neuropathy.
- Diabetes, especially with poor glucose control, is the most common cause of autonomic neuropathy. It can gradually cause nerve damage throughout the body.
- Certain medications, including some drugs used in cancer chemotherapy.
- Certain infectious diseases. Some viruses and bacteria, such as botulism, Lyme disease and HIV, can cause autonomic neuropathy.
- Inherited disorders. Certain hereditary disorders can cause autonomic neuropathy.
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. Amyloidosis, porphyria, hypothyroidism and cancer (usually due to side effects from treatment) also can increase the risk of autonomic neuropathy.
While certain inherited diseases that put you at risk of developing autonomic neuropathy can't be prevented, you can slow the onset or progression of symptoms by taking care of your health in general and managing your medical conditions.
Follow your doctor's advice on healthy living to control diseases and conditions, which 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.