Diabetic neuropathy

Diabetic neuropathy is a type of nerve damage that can happen with diabetes. Blood sugar, also called glucose, becomes high because of diabetes. Over time, high blood sugar 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 may include pain and numbness in the legs, feet and hands. It also can cause problems with the digestive system, urinary tract, blood vessels and heart. Some people have mild symptoms. But for others, diabetic neuropathy can be painful and disabling.

Diabetic neuropathy is a serious health concern. It may affect up to half of people who have diabetes. But diabetic neuropathy often can be prevented. And people who have it can take steps to keep it from getting worse. The key is to tightly manage blood sugar and lead a healthy lifestyle.

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

The symptoms depend on the type of diabetic neuropathy you have and which nerves are affected. Usually, symptoms appear slowly over time. You may not notice anything is wrong until a lot of nerve damage has happened.

Peripheral sensorimotor neuropathy

This type of neuropathy also may 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. Symptoms often are worse at night. They may include:

• Loss of feeling, also called numbness, or less ability to feel pain or temperature changes.
• A tingling or burning feeling.
• Sharp pains or cramps.
• Muscle weakness.
• Being very sensitive 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, pupils, bladder, digestive system and sex organs. Diabetes can affect nerves in any of these areas. That can cause symptoms including:

• A lack of the usual warning symptoms that let you know when blood sugar levels are low. This is called hypoglycemia unawareness.
• Drops in blood pressure when rising from sitting or lying down. This is called orthostatic hypotension. It can cause dizziness or fainting.
• A fast-beating heart while at rest.
• Bladder or bowel problems.
• Slow stomach emptying, also called gastroparesis. This can cause upset stomach, vomiting, a feeling of fullness and loss of appetite.
• Trouble swallowing.
• Changes in the way the eyes adjust from light to dark or far to near.
• More or less sweating than usual.
• Problems with sexual response. For instance, some people may have vaginal dryness or trouble feeling aroused. Others may have trouble getting or keeping an erection.

Proximal neuropathy

This type of neuropathy also is called diabetic polyradiculopathy. It often affects nerves in the thighs, hips, buttocks or legs. It can affect the stomach area and chest area. Symptoms often are on one side of the body. Rarely, they spread to the other side. Proximal neuropathy may include:

• Serious pain in the buttock, hip or thigh.
• Weak and shrinking thigh muscles.
• Trouble rising from a sitting position.
• Pain in the chest or the walls of the stomach area.

Mononeuropathy

This type of neuropathy also is called focal neuropathy. It damages a single, specific nerve. That nerve may be in the face, torso, arm or leg. It’s possible for mononeuropathy to affect single nerves in different parts of the body at the same time. Mononeuropathy may lead to:

• Trouble focusing or seeing two images of the same object, also called double vision.
• Not being able to move one side of the face. This is called paralysis.
• 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 that makes it hard to lift the front part of the foot. This condition is known as foot drop.
• Pain in the front of the thigh.

Call your healthcare professional for a checkup 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 makes it hard to do daily activities or sleep.
• Changes in digestion, urination or sexual function.
• Dizziness and fainting.

Tests can check for diabetic neuropathy before a person has symptoms of it. These are called screening tests. Screening tests can find diseases early when they're easier to treat. The American Diabetes Association recommends that screening for diabetic neuropathy start:

• Right after you learn you have type 2 diabetes.
• Or five years after you're found to have type 1 diabetes.

After that, screening is recommended once a year.

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. This process may lead to diabetic neuropathy. High blood sugar also weakens the walls of the small blood vessels called capillaries that supply the nerves with oxygen and nutrients.

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

• Poor blood sugar control. Uncontrolled high blood sugar raises the risk of every medical complication that can happen with diabetes, including nerve damage.
• Diabetes history. The risk of diabetic neuropathy rises the longer you have diabetes, especially if your 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 raise the risk of diabetic neuropathy.
• Smoking. Smoking narrows and hardens the arteries, lowering blood flow to the legs and feet. This makes it harder for wounds to heal. It also damages the peripheral nerves.
• High blood pressure and high cholesterol. Both are linked with a higher risk of diabetic neuropathy.

Diabetic neuropathy can cause serious medical conditions, including:

• Hypoglycemia unawareness. Most often, blood sugar levels below 70 milligrams per deciliter (mg/dL) — 3.9 millimoles per liter (mmol/L) — cause shakiness, sweating and a fast heartbeat in people living with diabetes. But people who have autonomic neuropathy may not feel these warning signs.
• Loss of a toe, foot or leg. Nerve damage can cause a loss of feeling in the feet. That means even minor cuts can turn into sores or ulcers without being noticed. Sometimes, an infection can spread to the bone or lead to tissue death. Without fast treatment, a toe, foot or even part of the leg may need to be removed with surgery. This is called amputation.
• Urinary problems. If the nerves that control the bladder are damaged, the bladder may not empty fully when urinating. Bacteria can build up in the bladder and kidneys, causing urinary tract infections. Nerve damage also can affect the ability to feel the need to urinate or to control the muscles that release urine. This can lead to leakage, also called 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. That may lead to lightheadedness and fainting.
• Digestive problems. If nerve damage happens in the digestive tract, you may get constipation or diarrhea, or both. Diabetes-related nerve damage can lead to a condition in which the stomach empties too slowly or not at all. This is called gastroparesis. It can cause bloating and an upset stomach.
• Sexual conditions. Diabetic neuropathy often damages the nerves that affect the sex organs. Symptoms may include vaginal dryness, having trouble becoming aroused, and difficulty getting or keeping an erection. This is called erectile dysfunction.
• More or less sweating than usual. Nerve damage can disrupt how the sweat glands work. That makes it hard for the body to control its temperature properly.

You may be able to prevent or delay diabetic neuropathy and the medical problems that can happen with it. To do so, closely manage your blood sugar and take good care of your feet.

Blood sugar control

A blood test called the A1C test looks at your average blood sugar level for the past 2 to 3 months. The American Diabetes Association recommends that people with diabetes have an A1C test at least twice a year. You also might hear it called the glycosylated hemoglobin, hemoglobin A1C or HbA1c test.

A1C goals may need to be tailored to each person. But for most adults, the American Diabetes Association recommends an A1C of less than 7.0%. The goal may be higher for older adults or those with other medical conditions. If your blood sugar levels are higher than your goal, you may need to change how you manage your diabetes. Your healthcare professional might change your medicine or add medicine to your treatment plan. Or you might be told to change your diet or physical activity.

Foot care

Foot problems are common with diabetic neuropathy. Examples include sores that don't heal and ulcers. But you can prevent many of these problems. The key is to take good care of your feet at home. And have a thorough foot exam at least once a year. Also have your healthcare professional check your feet at each office visit.

Follow your healthcare professional's advice 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 to look at parts of your feet that are hard to see. Or ask a friend or family member to help check.
• 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. It might make fungus more likely to grow.
• Trim your toenails carefully. Cut your toenails straight across. File the edges gently so they are smooth. If you can't do this yourself, see a specialist in foot problems, called a podiatrist, for help.
• Wear clean, dry socks. Look for socks made of cotton or moisture-wicking fibers. The socks should not 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 give your toes space to move. A foot specialist can teach you how to buy properly fitted shoes. The specialist also can show you how to prevent problems such as corns and calluses. If you have Medicare, your plan may cover the cost of at least one pair of shoes each year.
• Protect your feet from the heat. Wear shoes if you walk on hot pavement or go to the beach. If you go barefoot outdoors, put sunscreen on the tops of your feet so they don't get sunburned.
• Boost blood flow to your feet. If you can, put your feet up while you sit. And throughout the day, wiggle your toes around for a few minutes. It also helps to move your ankles in and out as well as up and down.