Diabetic neuropathy Health Article

Definition

Diabetic neuropathy is a common complication of diabetes, in which nerves are damaged as a result of high blood sugar levels (hyperglycemia).

Alternative Names

Nerve damage - diabetic

Causes, incidence, and risk factors

People with diabetes commonly develop temporary or permanent damage to nerve tissue. Nerve injuries are caused by decreased blood flow and high blood sugar levels, and are more likely to develop if blood sugar levels are not well controlled.

Some people with diabetes will not develop nerve damage, while others may develop this condition early. On average, symptoms begin 10 to 20 years after the diabetes diagnosis. Approximately 50% of people with diabetes will eventually develop nerve damage.

Peripheral nerve injuries may affect nerves in the skull (cranial nerves) or nerves from the spinal column and their branches. This type of nerve injury (neuropathy) tends to develop in stages.

Autonomic neuropathies affect the nerves that regulate vital functions, including the heart muscle and smooth muscles.

Symptoms

Digestive tract:

• Constipation
• Diarrhea
• Nausea and vomiting
• Swallowing difficulty

Legs and arms:

• Deep pain, most commonly in the feet and legs
• Loss of the sense of warm or cold
• Muscle cramps
• Numbness (if the nerves are severely damaged, you may be unaware that a blister or minor wound has become infected)
• Tingling or burning sensation in the extremities, particularly the feet
• Weakness

Other symptoms:

• Dizziness
• Drooping eyelid
• Drooping face
• Drooping mouth
• Impotence
• Light-headedness when standing up (orthostatic hypotension)
• Loss of bladder control
• Rapid heart rate
• Speech impairment
• Vision changes

Note: Symptoms vary depending on the nerve(s) affected, and may include symptoms other than those listed. Symptoms usually develop gradually over years.

Signs and tests

Physical examination, including nervous system (neurological) and sensory tests, may diagnose neuropathies. A common early finding is the absence of ankle reflexes.

Health care providers often test for loss of sensation in the feet with a brush-like instrument called a monofilament.

Electrodiagnostic testing may be done.