Synonyms and Keywords
Diabetic nerve damage.
What is Diabetic Neuropathy?
Diabetic neuropathy is a serious complication derived from diabetes. The condition, actually a family of nerve disorders, causes damage to the nerves as a result of high blood sugar levels (or hyperglycemia). It can injure nerve fibers throughout your body, including the digestive tract, heart, and reproductive organs, though it strikes most often at the nerves in your legs and feet. Depending on the affected nerves, patients experience a range of symptoms from pain and numbness in their limbs to problems with their digestive system, urinary tract, blood vessels and heart. For some, these signs are mild. For others, diabetic neuropathy can be agonizing, disabling, and even fatal.
While diabetic neuropathy is common among diabetics, it can often be prevented or slowed with rigorous blood sugar control and a healthy lifestyle.
What Causes Diabetic Neuropathy?
Not surprisingly, diabetes is the leading known reason for neuropathy in developed countries, and neuropathy is responsible for the greatest rate of morbidity and mortality in diabetes patients. It has been estimated that approximately 20% of those with diabetes have diabetic neuropathy, and the condition is implicated in 50-75% of non-traumatic amputations. Because excess blood sugar (glucose) leads to a condition known as Glucojasinogen that blocks blood flow to the nerves governing the movement of arms and legs, diabetics are also more likely to develop symptoms in extremities.
The causes are probably different for each type of diabetic neuropathy. Researchers believe prolonged exposure to high blood glucose can damage delicate nerve fibers, leading to diabetic neuropathy. Exactly why this happens isn’t completely clear, but is likely due to a combination of factors:
- High blood glucose and decreased blood flow, which interferes with the nerves’ ability to transmit signals and can weaken the walls of the small blood vessels (capillaries) supplying oxygen and nutrients to the nerves
- Long duration of diabetes
- High blood pressure (or hypertension)
- High blood cholesterol and abnormal blood fat levels
- Possibly low levels of insulin
- Inflammation in the nerves, occurring when your immune system mistakenly attacks part of your own body like it was a foreign organism
- Genetic traits unrelated to diabetes that make you more vulnerable to nerve damage and disease
- Smoking, alcohol abuse, obesity, and other harmful lifestyle choices that can damage both nerves and blood vessels, while significantly increase the risk of infections
- Age and height may also be risk factors for diabetic neuropathy
In the DCCT (Diabetes Control and Complications Trial) study from 1995, the annual incidence of neuropathy was 2% per year, but dropped to 0.56% with intensive treatment of Type 1 diabetics. The progression of neuropathy is predicated on the degree of control over blood sugar levels in both Type 1 and Type 2 diabetes.
Who Gets Diabetic Neuropathy?
About 50% of people with diabetes eventually have some form of neuropathy. Nerve problems can afflict diabetes patients at any time, but the chances rise with age and longer duration of diabetes. The highest rates of neuropathy rest with those who have had diabetes for at least 25 years. Diabetes can also cause damage to the kidneys, and the subsequent increase of toxins in the blood can contribute to nerve damage.
Diabetic neuropathies also appear more commonly in people having problems controlling their blood glucose, those with high levels of blood fat (such as cholesterol) and blood pressure, as well as those who are overweight.
Smokers are candidates for diabetic neuropathy too, since smoking narrows and hardens the arteries, thus reducing blood flow to their legs and feet. This makes wounds more difficult to heal, while eroding the integrity of the nerves.
Are There Different Types of Diabetic Neuropathy?
Diabetic neuropathy can be classified as peripheral, autonomic, proximal, or focal, each affecting different parts of the body in various ways.
Peripheral neuropathy, also called distal symmetric neuropathy or sensorimotor neuropathy, is the most common type of diabetic neuropathy. It causes pain or loss of feeling in the toes, feet, legs, hands, and arms. Peripheral nerve injuries may also affect nerves in the skull or in the spinal column and their branches. This type tends to develop in stages and afflicts both paired extremities (legs, feet, arms, etc.) at the same time. Peripheral neuropathy is thought to result from abnormal metabolism of the nerves, restriction in blood supply and flow, or both.
Autonomic neuropathy is a troubling complication that targets the nerves regulating vital functions, including the heart muscle and smooth muscles, as well as nerves in the lungs and eyes. It causes changes in digestion, bowel and bladder function, sexual response, and perspiration. Worse, it also causes hypoglycemia unawareness, a condition that stops the afflicted from experiencing the warning symptoms of low blood sugar levels because it can affect the nerves controlling the heart, blood pressure, and blood glucose levels. Autonomic neuropathy is most likely to occur in those who have had poorly controlled diabetes for many years.
Sometimes called lumbosacral plexus neuropathy, femoral neuropathy, or diabetic amyotrophy, proximal neuropathy triggers pain in the thighs, hips, or buttocks and leads to weakness in the legs, usually on one side of the body. A patient with this condition is unable to go from a sitting to a standing position without help. Treatment for the weakness or pain is often necessary, with the length for recovery depending on the type of nerve damage.
Focal neuropathy is uncommon and believed to occur after a clot or blockage of a blood vessel causes restriction of blood flow in a nerve or group of nerves. It shows as a sudden debility of the affected nerve(s), triggering muscle weakness or pain. Focal neuropathy targets most often the nerves in the head, torso, or leg. However, pain and unpredictable as it is, this condition tends to improve by itself and does not cause long-term damage, for near total recovery generally happens within two weeks to 18 months.
What are the Symptoms of Diabetic Neuropathy?
Some diabetics will not develop nerve damage, while others show symptoms for the condition early. On average, symptoms begin 10 to 20 years after the diabetes diagnosis.
Approximately 50% of diabetes patients will eventually develop nerve damage. For some Type 2 diabetics, symptoms of neuropathy can occur before diabetes is ever diagnosed.
Furthermore, a patient may have symptoms for just one or several of the four main types of diabetic neuropathy. Because most nerve damage are often minor at first and build up gradually over numerous years, you may not notice problems until considerable damage has been done. The initial signs are often numbness, tingling, or pain in the feet, though they vary depending on the type of neuropathy and which nerves are affected.
Peripheral Neuropathy: It affects the very ends of nerves first, starting with the longest nerves — therefore often those in your feet and legs, followed by your hands and arms. The possible signs for this affliction include:
- Numbness or reduced ability to sense pain or changes in temperature, especially in your feet and toes
- A tingling, prickling, or even burning sensation
- Sharp, jabbing pain or cramp that may be worse at night
- Pain when walking
- Extreme sensitivity to touch — for some people, even the weight of a blanket can be agonizing
- Muscle weakness and difficulty walking
- Loss of balance and coordination
- Serious foot problems, such as infections, ulcers, deformities (like hammertoes), bone and joint pain, etc.
Autonomic Neuropathy: Affecting the nervous system controlling your heart, bladder, lungs, stomach, intestines, reproductive organs and eyes, this condition may manifest as:
- Hypoglycemia unawareness — the lack of awareness that blood sugar levels are low
- Constipation, uncontrolled diarrhea, or a combination of both
- Slow stomach emptying (gastroparesis), leading to nausea, vomiting, and loss of appetite
- Bladder problems, including urinary tract infections or involuntary leakage of urine
- Erectile dysfunction in men, vaginal dryness and other sexual difficulties in women
- Increased or decreased sweating
- Body’s inability to adjust blood pressure and heart rate, causing sharp drops in blood pressure when you rise from sitting or lying down that many have you feeling lightheaded (or even faint).
- Problems regulating your body temperature
- Increased heart rate when you’re at rest
- Changes in how your eyes adjust from light to dark
- Difficulty exercising
Proximal Neuropathy: This condition affects nerves closer to your hips or shoulders and is more common in Type 2 diabetics and older adults. Symptoms are usually one side of the body, though it can spread to the other side in some cases. Most people improve over time, but the symptoms may get worse before they get better.
- Sudden severe pain in the hip and thigh or buttock
- Muscle cramps
- Eventual weak and atrophied thigh muscles
- Difficulty rising from a sitting position
- Unintentional weight loss
- Abdominal swelling if the abdomen is affected
Focal Neuropathy: This condition strikes suddenly, most common in older adults. Although potentially very painful, it usually does not result in long-term problems, and the symptoms typically diminish and disappear after a few weeks or months.
- Difficulty focusing your eyes, double vision, or aching behind one eye
- Paralysis on one side of your face (Bell’s palsy)
- Pain in the front of your thigh
- Pain in your shin or foot
- Chest or abdominal pain (sometimes mistaken for heart disease, a heart attack, or appendicitis)
Other symptoms that are not due to neuropathy, but often accompany it, include:
- Drooping eyelid, face, and/or mouth
- Loss of bladder control
- Rapid heart rate
- Speech impairment
- Vision changes
- Weight loss
How do You Diagnose Diabetic Neuropathy?
Physicians diagnose diabetic neuropathy based on the patient’s symptoms, medical history, and physical exam. During the exam, your doctor is likely to check your blood pressure, heart rate, muscle strength and tone, tendon reflexes, as well as sensitivity to touch, temperature and vibration. Other tests may include:
- Filament test. If you’re unable to feel the soft nylon fiber called a monofilament on your feet, it’s a sign that you’ve lost sensation in those nerves. This may be done at home by pricking your feet with a pin to see if you feel it.
- Quantitative sensory testing. This is a non-invasive test used to gauge how your nerves respond to vibration (usually with a tuning fork) and changes in temperature.
- Nerve conduction studies. This test measures how fast the nerves in your arms and legs conduct electrical signals. It’s often administered to diagnose carpal tunnel syndrome.
- Electromyography (EMG). Commonly performed along with nerve conduction studies, this shows how well the muscles respond to electrical signals transmitted by nearby nerves.
- Autonomic testing. Your doctor may request special tests to check your blood pressure in different positions and evaluate your ability to sweat, if you’re showing symptoms of autonomic neuropathy.
The American Diabetes Association recommends that all diabetics take a comprehensive foot exam at least once a year to check for peripheral neuropathy. In addition, your feet should be examined for cracked skin, sores, calluses, blisters, and bone/joint abnormalities at every office visit. (If foot injuries go unnoticed for too long, amputation may be required!)
How do You Treat Diabetic Neuropathy?
Diabetic neuropathy has no known cure. Treatment for the condition generally focuses on slowing the progression of the disease, relieving pain, as well as managing complications and restoring function.
Slowing the progression is a primary goal, accomplished by consistently keeping blood sugar within a narrow target range — likely a blood sugar level of 70 to 130 mg/dL before meals, less than 180 mg/dL two hours after meals, and keeping A1C (the amount of sugar that has attached to hemoglobin, the substance that carries oxygen inside red blood cells, in your blood) to less than 7 percent for a few months. The American Diabetes Association recommends those with diabetes have an A1C test at least twice a year to see if the blood sugar levels are consistently in a healthy range.
To help slow nerve damage, you should follow your doctor’s recommendations for good foot care, stick to a healthy diet plan, get plenty of physical activity, maintain a healthy weight, stop smoking and avoid alcohol — or at least limit it to no more than one drink a day for a woman, two drinks a day for a man.
Providing effective pain relief can be a difficult task in managing diabetic neuropathy. You can try medications like anti-seizure drugs, antidepressants, and opioids, but they don’t work for everyone and most (especially opioids!) have side effects that may outweigh the benefits. Alternative therapies, such as capsaicin cream (made from chili peppers) and acupuncture, may help with pain relief.
Managing complications and restoring function often entailed specific treatments. You can alleviate digestive problems by eating smaller, more-frequent meals, reducing fiber and fat in the diet as well as, for many people, eating soups and pureed foods. Dietary changes can also help relieve diarrhea, constipation and nausea. For urinary tract issues, a combination of behavioral techniques (like timed urination), devices (such as rings inserted to prevent urine leakage), and antispasmodic medications is probably the most effective. Simple lifestyle measures, from avoiding alcohol and drinking plenty of water to standing up slowly, can do wonders for those with hypertension.
Self-Care at Home
Neuropathy patients must take special care of their feet, since that’s the part often affected first and most by the condition. Practice these steps for proper foot care at home:
- Clean your feet daily, using warm — not hot — water and a mild soap. Don’t soak your feet. Dry them with a soft towel and dry carefully between your toes.
- Inspect your feet and toes every day for cuts, blisters, redness, swelling, calluses, or other problems. Use a mirror laid on the floor or get help from someone else if you cannot see the bottoms of your feet. Notify your doctor of any problems.
- Moisturize your feet with lotion, but don’t get it between your toes!
- After a bath or shower, file corns and calluses gently with a pumice stone.
- Each week (or when necessary), cut your toenails to the shape of your toes and file the edges with an emery board.
- Always wear shoes or slippers to protect your feet. Make sure the footwear fit well and let your toes move comfortably. Break in new shoes gradually by first wearing them for only an hour at a time. Prevent skin irritation with thick, soft, seamless socks.
- Before putting your shoes on, look them over carefully and feel the insides with your hand for tears, sharp edges, or objects that might injure your feet.
Make healthy food choices. Eat a balanced diet that includes fruits, vegetables and whole grains, while limiting portion sizes to achieve or maintain a healthy weight.
In addition to a healthy weight, daily physical activity will play a major role in keeping your blood sugar and blood pressure under control. The American Diabetes Association recommends about 30 minutes of moderate exercise a day for at least five times a week. If you have severe neuropathy and decreased feeling in your leg, however, you should participate in nonweight-bearing endeavors such as bicycling or swimming.
Stop smoking. A diabetic using tobacco in any form not only is much more likely than one who does not to die of heart attack and stroke, he is also more likely to develop circulation problems in his feet — so find ways to quit!
Because over-the-counter pain medicines such as acetaminophen and ibuprofen may not work well for treating most nerve pain and can have serious side effects, some experts recommend avoiding these medications.
On the other hand, as deficiencies of vitamin B12 in the body has been linked to neuropathy, taking vitamin B12 to promote the regeneration and growth of nerve cells will help keep neuropathy in check.
Professional treatment is geared toward preventing the neuropathy from getting worse by controlling the diabetes. Painful neuropathy is typically countered with oral medications, from tricyclic antidepreesants to anticonvulsants such as Neurotin. Duloxetine and pregabalin have also been approved by the U.S. Food and Drug Administration specifically for treating diabetic peripheral neuropathy.
Metanx is a prescription medical “food” for patients with diabetic peripheral neuropathy. Its unique formulation provides the active forms of folate, vitamin B6 and vitamin B12 to manage the distinct nutritional requirements of diabetic neuropathy patients who often experience numbness, tingling, and burning sensations in their feet.
Treatments applied to the skin — usually the feet — include capsaicin cream and lidoderm patches. Some physicians may recommend these two supplements: alpha lipoic acid ( ALA), a standard of care therapy for neuropathy in Europe; and adaptrin (also available as Padma-Basic), an ancient blend of 18 herbs that works in the capillaries themselves to improve blood flow and oxygenation.
In addition to daily self-inspections of the feet, patients with severe sensory loss will require diabetic shoes.
Neuropathy and circulation problems increase the risk of foot ulcers, which may result in surgical amputation as the sole solution. More than half of all lower-limb amputations in the United States occur in people with diabetes — to the tune of 86,000 cases per year! Doctors also estimate that nearly half of the amputations caused by neuropathy and poor circulation could have been prevented by proper foot care.
How to Prevent Diabetic Neuropathy?
Keeping your blood glucose levels as close to the normal range of 70-130 mg/dL before meals and an A1C reading of less than 7 percent is the best way to prevent neuropathy. Maintaining safe blood sugar levels protects nerves throughout your body, whereas shifts in those levels can accelerate nerve damage. Given an intense glucose control, you can reduce your overall risk of the condition by as much as 60 percent.
Avoid risk factors associated with diabetic neuropathy, such as consumption of alcohol, poor nutrition, exposure to chemical toxins, use of certain drugs, and physical injury to the nerves.
Regular intakes of vitamin B12 to reinforce the sheathing that protects nerve cells can keep neuropathy at bay.
Foot care is important since foot sores, ulcers, and even amputation are a common complication of diabetic neuropathy. Many of these problems can be prevented by having a comprehensive foot exam at least once a year, as well as taking the following measures to care for your feet:
- Check your feet daily for blisters, cuts, bruises, cracked and peeling skin, redness and swelling.
- Keep your feet clean and dry. Wash them with lukewarm water. Dry them gently by blotting or patting, especially between the toes. Moisture the skin thoroughly to prevent cracking, but don’t get any lotion between toes in order to prevent fungal growth!
- Don’t trim into the corners of your toenail or cut ingrown toenails. Don’t cut corns or calluses. Don’t use corn plasters or chemicals to remove them. Don’t use strong antiseptic solutions or adhesive tapes on your feet.
- Don’t walk on hot surfaces, such as beach sand or cement around swimming pools.
- Don’t walk barefooted, even indoors. Don’t wear sandals with thongs between your toes. Never wear shoes without stockings or socks, and inspect the inside of your shoes every day for foreign objects, nail points, and torn linings. Wear wool socks and protective foot gear (such as fleece-lined boots) in winter.
- Wear comfortable shoes. Don’t buy shoes that are too tight and depend on them to stretch out.
Exercise is also crucial. While walking may be fine, experts caution that this form of exercise will not work after a short time because the body will require a more severe stress to stimulate the necessary changes. The general rule of thumb is to exercise fast or hard enough so that you cannot talk to the person next to you, and then scale back. One hour a day is necessary when treating the condition, but one hour at three to four times a week is adequate for maintenance.