Diabetic Nerve Damage
Diabetic neuropathy is a serious and common complication of type 1 and type 2 diabetes. It’s a type of nerve damage caused by uncontrolled high blood sugar levels. You may not initially have any symptoms. The condition usually develops slowly, sometimes over the course of several decades.
If you have diabetes and are experiencing numbness, tingling, pain, or weakness of your hands or feet, call your doctor. These are the early symptoms of peripheral neuropathy. In cases of severe or prolonged peripheral neuropathy, you may experience injuries or infections in your extremities. In some cases, these can lead to amputation. Damage to other nerves of the body can cause other symptoms. That’s why it’s important to regularly monitor your blood sugar levels and contact your doctor if have any symptoms of neuropathy.
It’s common for symptoms of neuropathy to appear gradually. In many cases, the first type of nerve damage to occur involves the nerves of the feet. This can lead to symptoms such as the sensation of pins and needles in your feet.
Symptoms vary depending on the nerves affected. Common signs and symptoms of diabetic neuropathy include:
- sensitivity to touch
- loss of sense of touch
- difficulty with coordination when walking
- numbness or pain in your extremities
- muscle weakness or wasting
- nausea and indigestion
- diarrhea or constipation
- dizziness upon standing
- excessive sweating
- vaginal dryness in women and erectile dysfunction in men
Symptoms may vary depending on the type of neuropathy you’re experiencing.
The term neuropathy is used to describe several types of nerve damage. In people with diabetes, there are four main types of neuropathy you may develop.
The most common form of neuropathy is peripheral neuropathy. Peripheral neuropathy usually affects the feet and legs, but it can also affect the arms or hands. Symptoms are varied, and can be mild to severe. They include:
- tingling or burning sensations
- extreme sensitivity to touch
- insensitivity to hot and cold temperatures
- pain or cramping
Some people experience these symptoms more often at night.
Peripheral neuropathy can also cause muscle weakness and the loss of reflexes, which may lead to changes in your mobility, gait, and balance. Changes in walking sometimes cause foot deformities and foot injuries.
In people with diabetes, the combination of neuropathy and poor blood circulation makes it more difficult for wounds to heal. This leads to greater risk of complications from foot injuries. If you have peripheral neuropathy, you may not feel an injury or sore on your foot. This can increase your risk of the injury becoming infected. Longer healing times can also increase your risk for infection. In extreme cases, infection can lead to amputation.
The second most common type of neuropathy in people with diabetes is autonomic neuropathy.
The autonomic nervous system runs the involuntary systems — the systems you have no conscious control over — of the body. Many body organs and muscles are controlled by this system, including your:
- digestive system
- sweat glands
- sex organs
- cardiovascular system
Nerve damage to the digestive system may cause constipation, trouble swallowing, or gastroparesis. Gastroparesis is a disorder that causes a delay in digestion and may worsen over time, leading to frequent nausea and vomiting. Delayed digestion often makes monitoring glucose levels more difficult, too. Additionally, symptoms of hypoglycemia, like sweating and heart palpitations, may be masked in people with autonomic neuropathy. This may also make it difficult to determine when your blood glucose levels are too low.
Autonomic neuropathy may also cause sexual problems. Men may have erectile dysfunction, and women may experience vaginal dryness or have difficulty achieving orgasm. Neuropathy in the bladder may cause incontinence or make it more difficult to fully empty your bladder.
Nerve damage to the cardiovascular system can cause changes in your heart rate and blood pressure. People with type 2 diabetes may experience a drop in blood pressure after sitting or standing, causing them to feel dizzy and light-headed.
Cardiovascular autonomic neuropathy is a leading risk factor for death. Autonomic neuropathy often makes it difficult to identify some of the symptoms of a heart attack. If you have autonomic neuropathy, you should know the other warning signs for heart attack, including:
- profuse sweating
- pain in the arm, back, neck, jaw, or stomach
- shortness of breath
A less common form of neuropathy is proximal neuropathy, also known as diabetic amyotrophy. This form of neuropathy is more commonly seen in older adults with type 2 diabetes. It most commonly affects the hips, thighs, and legs. Diabetic amyotrophy usually affects only one side of the body.
In severe cases, proximal neuropathy may cause you to lose enough muscle tone that you no longer have the ability to go from a sitting to a standing position without assistance. This type of nerve damage is often painful.
The final type of neuropathy is focal neuropathy, or mononeuropathy. This type of neuropathy occurs when there’s damage to one specific nerve or group of nerves, causing weakness in the affected area. It appears suddenly and is usually very painful.
Focal neuropathy may affect the head, upper body, or legs. Unlike the other forms of neuropathy, this type usually goes away in a few weeks or months, and leaves no lasting damage.
Symptoms of focal neuropathy include:
Diabetic neuropathy is caused by high blood sugar levels sustained over a long period of time. Other factors can lead to nerve damage, such as:
- damage to the blood vessels, such as damage done by high cholesterol levels
- mechanical injury, such as injuries caused by carpal tunnel syndrome
- lifestyle factors, such as smoking or alcohol use
Low levels of vitamin B-12 can also lead to neuropathy. Metformin (Glucophage), a common medicine used to manage the symptoms of diabetes, can cause lower levels of vitamin B-12. Talk to your doctor if you’re concerned about vitamin deficiency. A simple blood test can identify any vitamin deficiencies.
Your doctor and healthcare team can help diagnose and treat any nerve problems you may be experiencing. During your appointment, your doctor will ask about your symptoms and medical history. You’ll also have a physical examination. During the physical exam, your doctor will check your reflexes and level of sensitivity to vibration, temperature, and touch. They’ll also check your heart rate, blood pressure, and muscle tone.
Your doctor may do a filament test to test the sensitivity in your feet. During this test, your doctor will use a nylon fiber to check your limbs for any loss of sensation. A tuning fork may be used to test your vibration threshold. Your doctor may also test your ankle reflexes.
There’s no cure for diabetic neuropathy, but treatment can slow the progression of the condition. Treatment can also help you manage symptoms, such as pain and indigestion.
Slowing the disease’s progress
Keeping your blood sugar levels within a healthy range can slow the progression of neuropathy. It can also relieve some symptoms. Quitting smoking and exercising regularly can also be parts of a comprehensive treatment plan.
Always talk to your doctor or healthcare team before beginning a new fitness routine.
Medications may be used to treat pain caused by diabetic neuropathy. Talk to your doctor about the available medications and their possible side effects. You may also want to consider alternative therapies, such as acupuncture. Some people find that alternative therapies provide some relief when used in conjunction with medication.
If you have problems with digestion as a result of your neuropathy, your doctor may suggest you eat smaller meals more often and limit the amount of fiber and fat in your diet.
If you’re a female experiencing vaginal dryness, your doctor may give you lubricants. If you’re a male with erectile dysfunction, they may prescribe medication to manage your symptoms.
Diabetes is one of the leading causes of lower-leg amputation from nontraumatic events in the United States. If you have peripheral neuropathy, it’s important to take special care of your feet.
Diabetic neuropathy is preventable if you manage your blood sugar levels properly. To do this, be consistent in:
- monitoring your blood glucose levels
- taking your medications as prescribed
- managing your diet
- being active
Keeping your diabetes in check is the best way to prevent diabetic neuropathy.
If you do develop diabetic neuropathy, work closely with your doctor and follow their recommendations for managing and slowing the progression of your condition. This can help you reduce the damage to your nerves.
Written by: Carmella Wint and Joann Jovinelly
Medically reviewed on Jan 09, 2017 by Peggy Pletcher, MS, RD, LD, CDE