Diabetic neuropathy

Overview

Diabetic neuropathy is a type of nerve damage that can occur if you have diabetes. High blood sugar (glucose) can injure nerves throughout the body. Diabetic neuropathy most often damages nerves in the legs and feet.

Depending on the affected nerves, diabetic neuropathy symptoms include pain and numbness in the legs, feet and hands. It can also cause problems with the digestive system, urinary tract, blood vessels and heart. Some people have mild symptoms. But for others, diabetic neuropathy can be quite painful and disabling.

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.

Symptoms

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

Your symptoms depend on the type you have and which nerves are affected. Usually, symptoms develop gradually. You may not notice anything is wrong until considerable nerve damage has occurred.

Peripheral neuropathy

This type of neuropathy may also be called distal symmetric peripheral neuropathy. It's the most common type of diabetic 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 feeling
• Sharp pains or cramps
• Muscle weakness
• Extreme 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 damage

Autonomic neuropathy

The autonomic nervous system controls blood pressure, heart rate, sweating, eyes, bladder, digestive system and sex organs. Diabetes can affect nerves in any of these areas, possibly causing signs and symptoms including:

• A lack of awareness that blood sugar levels are low (hypoglycemia unawareness)
• Drops in blood pressure when rising from sitting or lying down that may cause dizziness or fainting (orthostatic hypotension)
• Bladder or bowel problems
• Slow stomach emptying (gastroparesis), causing nausea, vomiting, sensation of fullness and loss of appetite
• Difficulty swallowing
• Changes in the way the eyes adjust from light to dark or far to near
• Increased or decreased sweating
• Problems with sexual response, such as vaginal dryness in women and erectile dysfunction in men

Proximal neuropathy (diabetic polyradiculopathy)

This type of neuropathy 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. Proximal neuropathy may include:

• Severe pain in the buttock, hip or thigh
• Weak and shrinking thigh muscles
• Difficulty rising from a sitting position
• Chest or abdominal wall pain

Mononeuropathy (focal neuropathy)

Mononeuropathy refers to damage to a single, specific nerve. The nerve may be in the face, torso, arm or leg. Mononeuropathy may lead to:

• Difficulty focusing or double vision
• Paralysis on one side of the face
• Numbness or tingling in the hand or fingers
• Weakness in the hand that may result in dropping things
• Pain in the shin or foot
• Weakness causing difficulty lifting the front part of the foot (foot drop)
• Pain in the front of the thigh

When to see a doctor

Call your health care provider 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 (ADA) recommends that screening for diabetic neuropathy begin immediately after someone is diagnosed with type 2 diabetes or five years after diagnosis with type 1 diabetes. After that, screening is recommended once a year.

Causes

The exact cause of each type of neuropathy is unknown. Researchers think that over time, uncontrolled high blood sugar damages nerves and interferes with their ability to send signals, leading to diabetic neuropathy. High blood sugar also weakens the walls of the small blood vessels (capillaries) that supply the nerves with oxygen and nutrients.

Risk factors

Anyone who has diabetes can develop neuropathy. But these risk factors make nerve damage more likely:

• Poor blood sugar control. Uncontrolled blood sugar increases the risk of every diabetes complication, including nerve damage.
• Diabetes history. The risk of diabetic neuropathy increases the longer a person has diabetes, especially if blood sugar isn't well controlled.
• Kidney disease. Diabetes can damage the kidneys. Kidney damage sends toxins into the blood, which can lead to nerve damage.
• Being overweight. Having a body mass index (BMI) of 25 or more may increase the risk of diabetic neuropathy.
• Smoking. Smoking narrows and hardens the arteries, reducing blood flow to the legs and feet. This makes it more difficult for wounds to heal and damages the peripheral nerves.

Complications

Diabetic neuropathy can cause a number of serious complications, including:

• Hypoglycemia unawareness. Blood sugar levels below 70 milligrams per deciliter (mg/dL) — 3.9 millimoles per liter (mmol/L) — usually cause shakiness, sweating and a fast heartbeat. But people who have autonomic neuropathy may not experience these warning signs.
• Loss of a toe, foot or leg. Nerve damage can cause a loss of feeling in the feet, so even minor cuts can turn into sores or ulcers without being noticed. In severe cases, an infection can spread to the bone or lead to tissue death. Removal (amputation) of a toe, foot or even part of the leg may be necessary.
• Urinary tract infections and urinary incontinence. If the nerves that control the bladder are damaged, the bladder may not empty completely when urinating. Bacteria can build up in the bladder and kidneys, causing urinary tract infections. Nerve damage can also affect the ability to feel the need to urinate or to control the muscles that release urine, leading to leakage (incontinence).
• Sharp drops in blood pressure. Damage to the nerves that control blood flow can affect the body's ability to adjust blood pressure. This can cause a sharp drop in pressure when standing after sitting or lying down, which may lead to lightheadedness and fainting.
• Digestive problems. If nerve damage occurs in the digestive tract, constipation or diarrhea, or both are possible. Diabetes-related nerve damage can lead to gastroparesis, a condition in which the stomach empties too slowly or not at all. This can cause bloating and indigestion.
• Sexual dysfunction. Autonomic neuropathy often damages the nerves that affect the sex organs. Men may experience erectile dysfunction. Women may have difficulty with lubrication and arousal.
• Increased or decreased sweating. Nerve damage can disrupt how the sweat glands work and make it difficult for the body to control its temperature properly.

Prevention

You can prevent or delay diabetic neuropathy and its complications by closely managing your blood sugar and taking good care of your feet.

Blood sugar management

The ADA recommends that people living with diabetes have a glycated hemoglobin (A1C) test at least twice a year. This test indicates your average blood sugar level for the past 2 to 3 months.

A1C goals may need to be individualized, but for many adults, the ADA recommends an A1C of less than 7.0%. If your blood sugar levels are higher than your goal, you may need changes in your daily management, such as adding or adjusting your medications or changing your diet or physical activity.

Foot care

Foot problems, including sores that don't heal, ulcers and even amputation, are common complications of diabetic neuropathy. But you can prevent many of these problems by having a thorough foot exam at least once a year. Also have your health care provider check your feet at each office visit and take good care of your feet at home.

Follow your health care provider's recommendations for good foot care. To protect the health of your feet:

• Check your feet every day. Look for blisters, cuts, bruises, cracked and peeling skin, redness, and swelling. Use a mirror or ask a friend or family member to help examine parts of your feet that are hard to see.
• Keep your feet clean and dry. Wash your feet every day with lukewarm water and mild soap. Don't soak your feet. Dry your feet and between your toes thoroughly.
• Moisturize your feet. This helps prevent cracking. But don't get lotion between your toes because it might encourage fungal growth.
• Trim your toenails carefully. Cut your toenails straight across. File the edges carefully so that you have smooth edges. If you can't do this yourself, a specialist in foot problems (podiatrist) can help.
• Wear clean, dry socks. Look for socks made of cotton or moisture-wicking fibers that don't have tight bands or thick seams.
• Wear cushioned shoes that fit well. Wear closed-toed shoes or slippers to protect your feet. Make sure your shoes fit properly and allow your toes to move. A foot specialist can teach you how to buy properly fitted shoes and to prevent problems such as corns and calluses. If you qualify for Medicare, your plan may cover the cost of at least one pair of shoes each year.

Diagnosis

Your health care provider can usually diagnose diabetic neuropathy by performing a physical exam and carefully reviewing your symptoms and medical history.

Your health care provider typically checks your:

• Overall muscle strength and tone
• Tendon reflexes
• Sensitivity to touch, pain, temperature and vibration

Along with the physical exam, your health care provider may perform or order specific tests to help diagnose diabetic neuropathy, such as:

• Filament testing. A soft nylon fiber (monofilament) is brushed over areas of your skin to test your sensitivity to touch.
• Sensory testing. This noninvasive test is used to tell how your nerves respond to vibration and changes in temperature.
• Nerve conduction testing. This test measures how quickly the nerves in your arms and legs conduct electrical signals.
• Electromyography. Called needle testing, this test is often done along with nerve conduction studies. It measures electrical discharges produced in your muscles.
• Autonomic testing. Special tests may be done to determine how your blood pressure changes while you are in different positions, and whether your sweating is within the standard range.

Treatment

Diabetic neuropathy has no known cure. The goals of treatment are to:

• Slow progression
• Relieve pain
• Manage complications and restore function

Slowing progression of the disease

Consistently keeping your blood sugar within your target range is the key to preventing or delaying nerve damage. Good blood sugar management may even improve some of your current symptoms. Your health care provider will figure out the best target range for you based on factors including your age, how long you've had diabetes and your overall health.

Blood sugar levels need to be individualized. But, in general, the American Diabetes Association (ADA) recommends the following target blood sugar levels for most people with diabetes:

• Between 80 and 130 mg/dL (4.4 and 7.2 mmol/L) before meals
• Less than 180 mg/dL (10.0 mmol/L) two hours after meals

The ADA generally recommends an A1C of 7.0% or lower for most people with diabetes.

Mayo Clinic encourages slightly lower blood sugar levels for most younger people with diabetes, and slightly higher levels for older people with other medical conditions and who may be more at risk of low blood sugar complications. Mayo Clinic generally recommends the following target blood sugar levels before meals:

• Between 80 and 120 mg/dL (4.4 and 6.7 mmol/L) for people age 59 and younger who have no other medical conditions
• Between 100 and 140 mg/dL (5.6 and 7.8 mmol/L) for people age 60 and older, or for those who have other medical conditions, including heart, lung or kidney disease

Other important ways to help slow or prevent neuropathy from getting worse include keeping your blood pressure under control, maintaining a healthy weight and getting regular physical activity.

Relieving pain

Many prescription medications are available for diabetes-related nerve pain, but they don't work for everyone. When considering any medication, talk to your health care provider about the benefits and possible side effects to find what might work best for you.

Pain-relieving prescription treatments may include:

• Anti-seizure drugs. Some medications used to treat seizure disorders (epilepsy) are also used to ease nerve pain. The ADA recommends starting with pregabalin (Lyrica). Gabapentin (Gralise, Neurontin) also is an option. Side effects may include drowsiness, dizziness, and swelling in the hands and feet.

• Antidepressants. Some antidepressants ease nerve pain, even if you aren't depressed. Tricyclic antidepressants may help with mild to moderate nerve pain. Drugs in this class include amitriptyline, nortriptyline (Pamelor) and desipramine (Norpramin). Side effects can be bothersome and include dry mouth, constipation, drowsiness and difficulty concentrating. These medications may also cause dizziness when changing position, such as from lying down to standing (orthostatic hypotension).

  Serotonin and norepinephrine reuptake inhibitors (SNRIs) are another type of antidepressant that may help with nerve pain and have fewer side effects. The ADA recommends duloxetine (Cymbalta, Drizalma Sprinkle) as a first treatment. Another that may be used is venlafaxine (Effexor XR). Possible side effects include nausea, sleepiness, dizziness, decreased appetite and constipation.

Sometimes, an antidepressant may be combined with an anti-seizure drug. These drugs can also be used with pain-relieving medication, such as medication available without a prescription. For example, you may find relief from acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin IB, others) or a skin patch with lidocaine (a numbing substance).

Managing complications and restoring function

To manage complications, you may need care from different specialists. These may include a specialist who treats urinary tract problems (urologist) and a heart specialist (cardiologist) who can help prevent or treat complications.

The treatment you'll need depends on the neuropathy-related complications you have:

• Urinary tract problems. Some drugs affect bladder function, so your health care provider may recommend stopping or changing medications. A strict urination schedule or urinating every few hours (timed urination) while applying gentle pressure to the bladder area (below your bellybutton) can help some bladder problems. Other methods, including self-catheterization, may be needed to remove urine from a nerve-damaged bladder.
• Digestive problems. To relieve mild signs and symptoms of gastroparesis — indigestion, belching, nausea or vomiting — eating smaller, more frequent meals may help. Diet changes and medications may help relieve gastroparesis, diarrhea, constipation and nausea.

• Low blood pressure on standing (orthostatic hypotension). Treatment starts with simple lifestyle changes, such as not using alcohol, drinking plenty of water, and changing positions such as from sitting to standing slowly. Sleeping with the head of the bed raised 4 to 6 inches helps prevent high blood pressure overnight.

  Your health care provider may also recommend compression support for your abdomen and thighs (abdominal binder and compression shorts or stockings). Several medications, either alone or together, may be used to treat orthostatic hypotension.

• Sexual dysfunction. Medications taken by mouth or injection may improve sexual function in some men, but they aren't safe and effective for everyone. Mechanical vacuum devices may increase blood flow to the penis. Women may benefit from vaginal lubricants.

Self care

These measures can help you feel better overall and reduce your risk of diabetic neuropathy:

• Keep your blood pressure under control. If you have high blood pressure and diabetes, you have an even greater risk of complications. Try to keep your blood pressure in the range your health care provider recommends, and be sure to have it checked at every office visit.
• Make healthy food choices. Eat a balanced diet that includes a variety of healthy foods — especially vegetables, fruits and whole grains. Limit portion sizes to help achieve or maintain a healthy weight.

• Be active every day. Exercise helps lower blood sugar, improves blood flow and keeps your heart healthy. Aim for 150 minutes of moderate or 75 minutes of vigorous aerobic activity a week, or a combination of moderate and vigorous exercise. It's also a good idea to take a break from sitting every 30 minutes to get a few quick bursts of activity.

  Talk with your health care provider or physical therapist before you start exercising. If you have decreased feeling in your legs, some types of exercise, such as walking, may be safer than others. If you have a foot injury or sore, stick with exercise that doesn't require putting weight on your injured foot.

• Stop smoking. Using tobacco in any form makes you more likely to develop poor circulation in your feet, which can cause problems with healing. If you use tobacco, talk to your health care provider about finding ways to quit.

Alternative medicine

There are many alternative therapies that may help with pain relief on their own or in combination with medications. But check with your health care provider before using any alternative therapy or dietary supplement to make sure that you don't have any potential interactions.

For diabetic neuropathy, you may want to try:

• Capsaicin. Capsaicin cream, applied to the skin, can reduce pain sensations in some people. Side effects may include a burning feeling and skin irritation.
• Alpha-lipoic acid. This powerful antioxidant is found in some foods and may help relieve nerve pain symptoms in some people.
• Acetyl-L-carnitine. This nutrient is naturally made in the body and is available as a supplement. It may ease nerve pain in some people.
• Transcutaneous electrical nerve stimulation (TENS). This prescription therapy may help prevent pain signals from reaching the brain. TENS delivers tiny electrical impulses to specific nerve pathways through small electrodes placed on the skin. Although safe and painless, TENS doesn't work for everyone or for all types of pain.
• Acupuncture. Acupuncture may help relieve the pain of neuropathy, and generally doesn't have any side effects. Keep in mind that you may not get immediate relief with acupuncture and might require more than one session.

Coping and support

Living with diabetic neuropathy can sometimes be challenging. Support groups can offer encouragement and advice about living with diabetic neuropathy. Ask your health care provider if there are any in your area, or for a referral to a therapist. The ADA offers online support through its website. If you find yourself feeling depressed, it may help to talk to a counselor or therapist.

Preparing for your appointment

If you don't already see a specialist in treating metabolic disorders and diabetes (endocrinologist), you'll likely be referred to one if you start showing signs of diabetes complications. You may also be referred to a specialist in brain and nervous system problems (neurologist).

To prepare for your appointment, you may want to:

• Be aware of any pre-appointment restrictions. When you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.
• Make a list of any symptoms you're having, including any that may seem unrelated to the reason for the appointment.
• Make a list of key personal information, including any major stresses or recent life changes.
• Make a list of all medications, vitamins, herbs and supplements you're taking and the doses.
• Bring a record of your recent blood sugar levels if you check them at home.
• Ask a family member or friend to come with you. It can be difficult to remember everything your health care provider tells you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
• Make a list of questions to ask your health care provider.

Some basic questions to ask may include:

• Is diabetic neuropathy the most likely cause of my symptoms?
• Do I need tests to confirm the cause of my symptoms? How do I prepare for these tests?
• Is this condition temporary or long lasting?
• If I manage my blood sugar, will these symptoms improve or go away?
• Are there treatments available, and which do you recommend?
• What types of side effects can I expect from treatment?
• I have other health conditions. How can I best manage them together?
• Are there brochures or other printed material I can take with me? What websites do you recommend?
• Do I need to see a certified diabetes care and education specialist, a registered dietitian, or other specialists?

What to expect from your doctor

Your health care provider is likely to ask you a number of questions, such as:

• How effective is your diabetes management?
• When did you start having symptoms?
• Do you always have symptoms or do they come and go?
• How severe are your symptoms?
• Does anything seem to improve your symptoms?
• What, if anything, appears to make your symptoms worse?
• What's challenging about managing your diabetes?
• What might help you manage your diabetes better?