High blood sugar (glucose) can injure nerves throughout your body. Diabetic neuropathy most often damages nerves in your legs and feet. Diabetic neuropathy is a serious diabetes complication that may affect as many as 50% of people with diabetes. But you can often prevent diabetic neuropathy or slow its progress with consistent blood sugar management and a healthy lifestyle.

There are four main types of diabetic neuropathy. You can have one type or more than one type of neuropathy.

Peripheral neuropathy

It affects the feet and legs first, followed by the hands and arms. Signs and symptoms of peripheral neuropathy are often worse at night, and may include:

• Numbness or reduced ability to feel pain or temperature changes
• Tingling or burning sensation
• Sharp pains or cramps
• Increased sensitivity to touch — for some people, even a bedsheet's weight can be painful
• Serious foot problems, such as ulcers, infections, and bone and joint pain

Autonomic neuropathy

The autonomic nervous system controls your heart, bladder, stomach, intestines, sex organs and eyes. Diabetes can affect nerves in any of these areas, possibly causing:

• A lack of awareness that blood sugar levels are low (hypoglycemia unawareness)
• Bladder or bowel problems
• Slow stomach emptying (gastro paresis), causing nausea, vomiting and loss of appetite
• Changes in the way your eyes adjust from light to dark
• Decreased sexual response

Proximal neuropathy (diabetic polyradiculopathy)

This type of neuropathy — also called diabetic amyotrophic — often affects nerves in the thighs, hips, buttocks or legs. It can also affect the abdominal and chest area. Symptoms are usually on one side of the body, but may spread to the other side. You may have:

• Severe pain in a hip and thigh or buttock
• Eventual weak and shrinking thigh muscles
• Difficulty rising from a sitting position
• Severe stomach pain

Mononeuropathy (focal neuropathy)

There are two types of mononeuropathy — cranial and peripheral. Mononeuropathy refers to damage to a specific nerve. Mononeuropathy may also lead to:

• Difficulty focusing or double vision
• Aching behind one eye
• Paralysis on one side of your face (Bell's palsy)
• Numbness or tingling in your hand or fingers, except your pinkie (little finger)
• Weakness in your hand that may cause you to drop things

When to see a doctor

Call your doctor for an appointment if you have:

• A cut or sore on your foot that is infected or won't heal
• Burning, tingling, weakness or pain in your hands or feet that interferes with daily activities or sleep
• Changes in digestion, urination or sexual function
• Dizziness and fainting

The American Diabetes Association recommends that screening for diabetic neuropathy begin immediately after someone is diagnosed with type 2 diabetes, and five years after diagnosis for someone with type 1 diabetes. After that, screening is recommended annually.