Diabetic nerve damage (neuropathy) Whakamōtī akaaka mate huka

Over time, high levels of glucose in your blood can change the chemicals in your nerves and cause damage. 

High blood glucose levels can also damage the small blood vessels that nourish your nerves with oxygen and nutrients. Without enough oxygen and nutrients, your nerves cannot function well.

The 3 main types of neuropathy are sensory, motor and autonomic. These can cause different symptoms, depending on the affected body part.

Nerve damage can happen very slowly, and you may not notice the changes.

Sensory neuropathy

Sensory neuropathy is the most common type. It usually affects nerves in your feet and legs but can sometimes affect nerves in your hands and arms.

Sensory neuropathy can cause a feeling of numbness, tingling or pins and needles. Some people develop a feeling as if they are walking over sharp stones.

It is sometimes called painful neuropathy because it may also cause:

• burning pains in your legs, especially in bed at night
• shooting pains
• over-sensitivity to even the slight touch.

You may not notice any symptoms but still have signs of sensory neuropathy when your feet are tested.

Sensory neuropathy can lead to foot problems such as ulcers and skin infections. The nerve damage can make you lose feeling in your feet, so you may not notice if your shoes are causing a blister or that you have a split in your skin. These may get infected or cause an ulcer. It is important you check your feet regularly. 

Check your feet

Motor neuropathy

Motor neuropathy is less common. It might cause weak muscles, especially in your legs. It can alter the shape of your feet and cause problems with shoes. Both of these might lead to problems with walking.

Autonomic neuropathy

Autonomic neuropathy affects the nerves that control internal organs. Autonomic nerves carry signals to help with many of the things you do without thinking, such as:

• sweating
• digestion
• blood pressure and heart rate control.

The symptoms depend on where the problem is. You could have:

• a sick feeling (nausea) or be throwing up (vomiting) if it affects your stomach
• hard poos (constipation) or runny poos (diarrhoea) if it affects your intestines
• difficulty weeing if it affects your bladder
• problems with erections if it affects your penis
• dizziness and palpitations if it affects your heart and blood vessels
• dry skin, especially on your feet, if it affects your sweat glands.

Your healthcare provider will ask you questions about your symptoms and medical history. They will also give you a physical exam.

During the exam, they may check:

• your overall muscle strength and tone
• the reflexes of your muscles and tendons
• how sensitive you are to touch, pain, temperature and vibration.

You may need to have additional tests to help confirm whether or not you have diabetic neuropathy.

Diabetic neuropathy can be treated but not cured. Treatment can:

• help prevent the condition from getting worse (particularly by keeping your blood sugar within your target range)
• relieve pain
• help the parts of the body affected by neuropathy to function better.

There are a range of medicines that may help relieve neuropathic pain. Many of them were originally designed for another medical condition but have also been found to work for nerve pain. These include: 

• tricyclic antidepressant drugs such as amitriptyline and nortriptyline
• anticonvulsants such as gabapentin and pregabalin.

Some people have found pain relief from capsaicin cream.

Capsaicin cream — Healthify

A therapy called TENS (transcutaneous electrical nerve stimulation) can also provide relief from pain. TENs uses mild electrical currents to stimulate nerves. This therapy is often available through health providers who specialise in pain management.

Other health providers can also help:

• Physiotherapists — can help with your movements, especially if you have muscle pain and weakness.
• Occupational therapists — can help improve your ability to do your every day tasks.
• Speech therapist — can help if you have nerve damage that affects your ability to swallow (dysphagia).

It is important to tell your healthcare provider if your medication is not working or is causing side effects. They may refer you to a specialist diabetes service or to a pain clinic for other forms of treatment.

Keep your blood glucose levels under control to stop your diabetic neuropathy getting worse.

You should also:

• not smoke
• eat well
• keep physically active every day
• limit alcohol
• get 7 to 8 hours of sleep each night

Look after your feet. If you have reduced feeling in your feet, you are at risk of foot problems, including ulcers.

Check your feet every day. If you find a problem, contact your podiatrist or diabetes healthcare provider.

Self‑care for diabetic foot problems

You will also need your feet checked by a podiatrist at least once a year.