Diabetic neuropathy is nerve damage that results from diabetes. The damaged nerves can then cause a variety of symptoms, ranging from numbness to disabling pain. Experts don’t know exactly how diabetes causes neuropathy, but elevated blood sugar and autoimmune inflammation appear to impair circulation and injure your nerves.
Diabetic neuropathy is the most common complication of type 1 diabetes but also affects those with type 2 diabetes. Overall, diabetic neuropathy affects up to half of all people with diabetes.
Types of diabetic neuropathy
There are four different types of neuropathy in diabetics:
- Peripheral neuropathy
- Autonomic neuropathy
- Radiculoplexus neuropathy
Peripheral neuropathy: Peripheral neuropathy is the most common type of neuropathy in diabetics. Peripheral neuropathy typically attacks your feet and legs, followed by your hands and arms. According to the National Diabetes Information Clearinghouse, at least half of those with diabetes have some form of peripheral neuropathy.
The symptoms of peripheral neuropathy include:
- Numbness and tingling
- Loss of sensation
- An inability to sense temperature changes or feel external pain
- Burning, sensitivity to touch, or pain in your feet, legs, hands, or arms
Over time, peripheral neuropathy in the feet or legs can make you lose your balance, putting you at higher risk of injury. Loss of sensation and circulation in the feet also puts you at higher risk of non-healing foot ulcers and infections, which in some cases, can lead to amputation.
Autonomic neuropathy: Autonomic neuropathy attacks the function of your heart, bladder, intestines, stomach, sex organs, and eyes. Some autonomic neuropathy symptoms include:
- Urinary tract infections
- Constipation, diarrhea, or both
- Gastroparesis – slow emptying of your stomach – which can cause nausea, loss of appetite, bloating and vomiting
- Difficulty swallowing
- An increase or decrease in sweating
- Trouble controlling your body temperature
- An elevated resting heart rate
- Drops in blood pressure when changing your position, making you feel dizzy or faint
- Erectile dysfunction
- Vaginal dryness
Radiculoplexus neuropathy: Radiculoplexus neuropathy is also known as diabetic amyotrophy and affects the nerves in your thighs, hips, buttocks, or legs. It is more commonly seen in type 2 diabetes. Symptoms usually appear on one side of your body and can include:
- Pain in your hips, thighs or buttocks
- Loss of muscle in your thighs
- Difficulty getting up from sitting
- Swelling in your abdomen
- Weight loss
Mononeuropathy: Mononeuropathy is also known as focal neuropathy and refers to damage to an individual nerve that causes severe pain. Symptoms include pain in your shin, foot, lower back, pelvis, thigh, chest, abdomen, or behind your eyes.
Mononeuropathy can also result in a compressed nerve, causing carpal tunnel or tarsal tunnel syndrome, with symptoms including pain, numbness, tingling, or weakness in the fingers, hand, wrist, toes, feet, and ankles.
Diagnosing diabetic neuropathy
Diagnosing diabetic neuropathy requires a review of your symptoms, along with a physical exam to test your:
- muscle strength and tone
- sensitivity to touch and vibration
Your doctor may perform other tests, such as:
- A filament test on your feet
- Tests to evaluate your response to vibration and temperature changes
- Nerve conduction studies for arms and legs
- Electromyography (EMG) to evaluate your muscles
- Autonomic testing to assess blood pressure and sweating abnormalities
- Gastric emptying test
- Ultrasound of the bladder or urinary tract
Treatment of diabetic neuropathy
There is no cure for diabetic neuropathy. Treatments for the condition focus on controlling your blood sugar to slow the progression of neuropathy, pain relief, maintaining your physical abilities, and treating your related conditions and symptoms.
Maintain tight blood sugar control to slow the progression of neuropathy: Tight blood sugar control is the foundation of any efforts to prevent, manage, or reverse diabetic neuropathy. You should strive to keep your A1C levels below 5.7 percent, according to the National Institute of Diabetes and Digestive and Kidney Diseases.
Specifically, the American Diabetes Association generally recommends the following target blood sugar levels:
- Between 80 and 120 mg/dL (4.4 and 6.7 mmol/L) before meals
- Less than 180 mg/dL (10.0 mmol/L) two hours after meals
Your blood sugar management approach should include the following activities:
- Hemoglobin A1C (A1C) testing twice a year.
- Daily blood sugar monitoring. (Note: the use of a continuous glucose monitor (CGM) is a proven way to improve blood sugar control and lower AIC levels.)
- Optimal insulin therapy and management of carbohydrate intake.
Relieve neuropathy pain: Your doctor may prescribe drugs for neuropathy pain. These drugs include:
- Anti-seizure medications such as pregabalin (Lyrica), gabapentin (Gralise, Neurontin) and carbamazepine (Carbatrol, Tegretol)
- Tricyclic antidepressants such as amitriptyline, desipramine (Norpramin) and imipramine (Tofranil), and serotonin and norepinephrine reuptake inhibitors (SNRIs) such as duloxetine (Cymbalta) and venlafaxine (Effexor XR)
- A cannabinoid drug like Nabilone
In some cases, topical medications for pain like topical clonidine and lidocaine – as well as over-the-counter capsaicin cream – can help.
Your doctor may also recommend transcutaneous electrical nerve stimulation (TENS) therapy. A TENS unit delivers electrical signals to your nerve pathways, helping to block pain signals from reaching your brain.
Some research has found that acupuncture may be effective at reducing or managing pain associated with peripheral neuropathy.
Maintain physical abilities: In some cases, physical therapy may help improve your mobility and balance and maintain your muscle strength. Your doctor may recommend occupational therapy if your peripheral neuropathy requires you to use adaptive devices, such as grab bars, elevated toilet seats, extendable reachers, and other equipment.
Treat related symptoms and conditions: Your doctor may prescribe drugs to treat neuropathy-related conditions and symptoms such as:
- urinary tract infections
- erectile dysfunction
- vaginal dryness
- autonomic dysfunction
If you have gastroparesis as a result of neuropathy, your doctor may recommend a specialized diet designed to minimize the symptoms.
If you have autonomic dysfunction due to autonomic neuropathy, your doctor may recommend dietary changes and modification of your salt and fluid intake. You may also find compression stockings or abdominal binders helpful in avoiding significant drops in your blood pressure when standing.
Lifestyle changes: Your doctor may recommend that you follow a lower-fat, carbohydrate-controlled diet and get regular exercise, which may slow the progression of your neuropathy. It's also especially important to stop smoking because it can worsen symptoms of neuropathy.
Supplements for diabetic neuropathy
Several dietary supplements show promise as primary or complementary treatments for diabetic neuropathy.
Vitamin B-12: There is a high rate of vitamin B-12 deficiency in people with diabetes. Some research has shown that vitamin B-12 supplementation may help relieve the symptoms of diabetic neuropathy.
Alpha-lipoic acid: Research shows that the antioxidant supplement alpha-lipoic acid reduced pain and improved nerve function in some diabetic neuropathy patients. Alpha lipoic acid is an approved treatment for diabetic peripheral neuropathy in Europe, but not the U.S.
Acetyl-L-carnitine: Several clinical trials have found the supplement acetyl-L-carnitine helpful in pain reduction and improved nerve function, especially when started early in the course of diabetic neuropathy. (Note: Acetyl-L-carnitine is not recommended for people with hypothyroidism, as it can slow the thyroid gland.)
Benfotiamine: Most people with diabetes have low levels of vitamin B1/thiamine and research has found that correcting these low levels may decrease the risk of diabetic neuropathy. The best way to restore thiamine levels is a form of thiamine called benfotiamine. High doses of around 40 mg per day were found to significantly reduce pain from diabetic neuropathy within three weeks of starting the therapy.
Self-care for your feet
Peripheral neuropathy in your feet increases your risk of foot ulcers, which then puts you at risk of amputation. Around 67 percent of amputations in the United States are attributable to diabetes. At the same time, 75 percent of all diabetic foot ulcers are preventable.
How do you prevent foot ulcers? Most importantly, you first need to be aware that you have peripheral neuropathy. Keep in mind that most people with neuropathy in the feet aren’t aware of it. One study of people over the age of 61 found that more than 90 percent of them were unaware they had diabetic neuropathy in their feet. For early detection of peripheral neuropathy in your feet, you should:
- Perform a home monofilament test for peripheral neuropathy every three months. You can get a low-cost test kit from Fit2Walk. The kit includes filaments, instructions, and a foot mirror. You press the filament to four different areas of each foot for a few seconds.
- Have an annual foot exam by your health care provider
Everyone with diabetes should perform a daily foot check. Look for sores, redness, cracked skin, wounds, bruising, blisters, injuries, and discoloration. Use a magnifying mirror to help closely examine your feet. If you can't check your own feet, have someone else do it for you.
Some other ways to help prevent foot ulcers:
- Check your footwear for any foreign objects before wearing
- Keep your feet clean and dry
- Wiggle your toes and move your ankles frequently throughout the day, to keep blood flowing to feet and toes
- Wear socks that don’t have elastic bands. (You may want to wear special diabetic socks, which help keep your feet dry, prevent blisters, and aren’t binding.)
- See your doctor right away to treat any injuries to your feet.
Can you prevent or reverse diabetic neuropathy?
You may be able to prevent or reverse diabetic neuropathy. The key? It all comes down to managing blood sugar.
According to the National Institute of Diabetes and Digestive and Kidney Diseases’ report, Diabetic Neuropathies: The Nerve Damage of Diabetes:
The best way to prevent neuropathy is to keep blood glucose levels as close to the normal range as possible.
Tight blood sugar control is defined as:
- An A1C level below 5.7 percent
- A blood sugar level between 80 and 120 mg/dL (4.4 and 6.7 mmol/L) before meals
- A blood sugar of less than 180 mg/dL (10.0 mmol/L) two hours after meals
Researchers have found, in fact, that strict blood sugar control reduces the risk of neuropathy, slows the progression, can significantly reduce the incidence of neuropathy in type 1 diabetics by up to 70 percent!
Diabetes expert Richard Bernstein MD, bestselling author of Dr. Bernstein’s Diabetes Solution, believes that rigorous blood sugar control can prevent diabetic neuropathy, along with other complications of diabetes. Dr. Bernstein reports that he has seen some patients achieve a partial or full remission of their existing diabetic neuropathy symptoms over time when they keep blood sugar levels low and controlled.