There are three types of diabetic nerve damage:
- Peripheral neuropathy
- Autonomic neuropathy
- Focal neuropathy
By far the most common form of neuropathy, accounting for the majority of cases in people with diabetes, is peripheral neuropathy. Peripheral neuropathy typically manifests itself in the feet, because the nerves running from the brain to the feet are the longest in the body, which makes them the most vulnerable to degradation.
Symptoms of peripheral neuropathy include pain, tingling, a burning sensation or numbness in the feet and legs and sometimes in the hands as well. Once nerve function is compromised, the damage is generally progressive and irreversible.
Autonomic neuropathy affects involuntary systems like digestion, breathing, urination and sexual function. Diabetes can affect the nerves in any of these areas, potentially causing symptoms like:
- Urinary incontinence
- Constipation or diarrhea
- Slow stomach emptying—called gastroparesis—leading to nausea and vomiting
- Erectile dysfunction in men
- Vaginal dryness and other sexual difficulties in women
- Increased or decreased sweating
- Problems regulating body temperature and blood pressure
- Rapid heart rate when at rest
Autonomic neuropathy is most likely to occur in people who have had poorly controlled diabetes for many years.
Focal neuropathy (also called mononeuropathy) causes damage to one nerve, such as in the arm, leg or face, or a localized group of nerves, such as those involved in vision. An eyelid or one side of your face might sag as a result, or your vision may become blurry.
Focal neuropathy often comes on suddenly and can cause severe pain, but symptoms usually go away on their own over the course of a few weeks or months.
From our sister publication, Diabetes Focus (Summer 2011)