Diabetic neuropathy
DEFINITION
Diabetic neuropathy is a type of nerve damage that can occur if you have diabetes. High blood sugar can injure nerve fibers throughout your body, but diabetic neuropathy most often damages nerves in your legs and feet.
Depending on the affected nerves, symptoms of diabetic neuropathy can range from pain and numbness in your extremities to problems with your digestive system, urinary tract, blood vessels and heart. For some people, these symptoms are mild; for others, diabetic neuropathy can be painful, disabling and even fatal.
Diabetic neuropathy is a common serious complication of diabetes. Yet you can often prevent diabetic neuropathy or slow its progress with tight blood sugar control and a healthy lifestyle.
CAUSES
Damage to nerves and blood vessels
- Prolonged exposure to high blood sugar can damage delicate nerve fibers, causing diabetic neuropathy. Why this happens isn’t completely clear, but a combination of factors likely plays a role, including the complex interaction between nerves and blood vessels.
- High blood sugar interferes with the ability of the nerves to transmit signals. It also weakens the walls of the small blood vessels (capillaries) that supply the nerves with oxygen and nutrients.
Other factors
Other factors that may contribute to diabetic neuropathy include:
- Inflammation in the nerves caused by an autoimmune response. This occurs when your immune system mistakenly attacks part of your body as if it were a foreign organism.
- Genetic factors unrelated to diabetes that make some people more susceptible to nerve damage.
- Smoking and alcohol abuse, which damage both nerves and blood vessels and significantly increase the risk of infections.
SYMPTOMS
There are four main types of diabetic neuropathy. You may have just one type or symptoms of several types. Most develop gradually, and you may not notice problems until considerable damage has occurred.
The signs and symptoms of diabetic neuropathy vary, depending on the type of neuropathy and which nerves are affected.
Peripheral neuropathy
Peripheral neuropathy is the most common form of diabetic neuropathy. Your feet and legs are often affected first, followed by your 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
- A tingling or burning sensation
- Sharp pains or cramps
- Increased sensitivity to touch — for some people, even the weight of a bed sheet can be agonizing
- Muscle weakness
- Loss of reflexes, especially in the ankle
- Loss of balance and coordination
- Serious foot problems, such as ulcers, infections, deformities, and bone and joint pain
Autonomic neuropathy
The autonomic nervous system controls your heart, bladder, lungs, stomach, intestines, sex organs and eyes. Diabetes can affect the nerves in any of these areas, possibly causing:
- A lack of awareness that blood sugar levels are low (hypoglycemia unawareness)
- Bladder problems, including urinary tract infections or urinary retention or incontinence
- Constipation, uncontrolled diarrhea or a combination of the two
- Slow stomach emptying (gastroparesis), leading to nausea, vomiting, bloating and loss of appetite
- Difficulty swallowing
- Erectile dysfunction in men
- Vaginal dryness and other sexual difficulties in women
- Increased or decreased sweating
- Inability of your body to adjust blood pressure and heart rate, leading to sharp drops in blood pressure after sitting or standing that may cause you to faint or feel lightheaded
- Problems regulating your body temperature
- Changes in the way your eyes adjust from light to dark
- Increased heart rate when you’re at rest
Radiculoplexus neuropathy (diabetic amyotrophy)
Radiculoplexus neuropathy affects nerves in the thighs, hips, buttocks or legs. Also called diabetic amyotrophy, femoral neuropathy or proximal neuropathy, this condition is more common in people with type 2 diabetes and older adults.
Symptoms are usually on one side of the body, though in some cases symptoms may spread to the other side. Most people improve at least partially over time, though symptoms may worsen before they get better. This condition is often marked by:
- Sudden, severe pain in your hip and thigh or buttock
- Eventual weak and atrophied thigh muscles
- Difficulty rising from a sitting position
- Abdominal swelling, if the abdomen is affected
- Weight loss
Mononeuropathy
Mononeuropathy involves damage to a specific nerve. The nerve may be in the face, torso or leg. Mononeuropathy, also called focal neuropathy, often comes on suddenly. It’s most common in older adults.
Although mononeuropathy can cause severe pain, it usually doesn’t cause any long-term problems. Symptoms usually diminish and disappear on their own over a few weeks or months. Signs and symptoms depend on which nerve is involved and may include:
- Difficulty focusing your eyes, double vision or aching behind one eye
- Paralysis on one side of your face (Bell’s palsy)
- Pain in your shin or foot
- Pain in your lower back or pelvis
- Pain in the front of your thigh
- Pain in your chest or abdomen
Sometimes mononeuropathy occurs when a nerve is compressed. Carpal tunnel syndrome is a common type of compression neuropathy in people with diabetes.
Signs and symptoms of carpal tunnel syndrome include:
- Numbness or tingling in your fingers or hand, especially in your thumb, index finger, middle finger and ring finger
- A sense of weakness in your hand and a tendency to drop things
When to see a doctor
Seek medical care if you notice:
- A cut or sore on your foot that doesn’t seem to be healing, is infected or is getting worse
- Burning, tingling, weakness or pain in your hands or feet that interferes with your daily routine or your sleep
- Dizziness
- Changes in your digestion, urination or sexual function
- These signs and symptoms don’t always indicate nerve damage, but they may signal other problems that require medical care. Early diagnosis and treatment offer the best chance for controlling symptoms and preventing more-severe problems.
- Even minor sores on the feet that don’t heal can turn into ulcers. In the most severe cases, untreated foot ulcers may become gangrenous — a condition in which the tissue dies — and require surgery or even amputation of your foot. Early treatment can help prevent this from happening.
