Peripheral neuropathy is a disorder that affects the peripheral nervous system. This is one of the two components of the nervous system. The other component is the central nervous system (brain and spinal cord).
How the Peripheral Nerves Work
The peripheral nervous system is made up of peripheral nerves. They reach all parts of your body apart from brain and spinal cord. These nerves control how you sense touch and feel pain and temperature. They also control your muscle strength and coordination.
The peripheral nerves carry information to and from the central nervous system. They allow your feet, arms, and organs to send information to your brain. For example, they tell the central nervous system that you feel pain when you step on a tack, or that your hands are cold.
In turn, the central nervous system uses the peripheral nerves to send signals to your body. These signals are "orders" to your muscles and organs. That's how you're able to move, breathe, and maintain your balance.
Damage to Peripheral Nerves
The peripheral nerves are fragile. Whey they suffer injury, they can no longer perform their function well.
Damage to peripheral nerves affects how the central and peripheral nervous systems communicate. Damaged communication between the two can lead to loss of sensation. For example, you may become unable to feel a burn from hot water. Or, damaged nerves can lead to loss of function, like being unable to maintain balance when you walk. This, in turn, increases your risk of injuries and falls.
Often, peripheral neuropathy can cause discomfort, numbness, and tingling. It may also lead to weakness in the feet, hands, legs, and arms. Sometimes it causes pain. And some neuropathies may limit your mobility. Your condition might make you unable to enjoy simple everyday activities. Even walking can become difficult.
All these symptoms can disrupt your life. But not all types of peripheral neuropathy are crippling. And treatment is available for many neuropathies. To prescribe the right treatment, doctors first need to discover the cause of the disease.
Causes of Peripheral Neuropathy
Peripheral neuropathy is a very common condition. It affects about 6 percent of the U.S. population, or more than 20 million people.
It can have various causes. The most common is diabetes. About 60 percent of people with diabetes will develop peripheral neuropathy. That's because high blood sugar levels can damage the nerves.
Another common cause of peripheral neuropathy is nerve injury or trauma. This can result from auto collisions, sports accidents, medical procedures, and more.
For example, all of the following can cause injury to nerve tissue:
• Cutting or tearing
• Electrical injury
• Gunshot wound
Not only injury but also compression can harm the nerve tissue. For example, the carpal tunnel syndrome is a type of compression peripheral neuropathy. It affects the hands. Its cause is repetitive motions that put pressure on a nerve.
Other causes of peripheral neuropathy include the following:
• Autoimmune disorders
• Heavy metal exposure (for example, lead poisoning)
• Exposure to toxic chemicals, such as solvent
• Infections (including Lyme disease, AIDS, and hepatitis C)
• Vitamin deficiency (for example, B1, B6, B12)
• Kidney disease
• Metabolic disease
Peripheral neuropathy is also a side effect of certain types of medication. One example is chemotherapy drugs.
In rare cases, peripheral neuropathy runs in the family. This means that parents can pass it to their children. Inherited peripheral neuropathy includes the Charcot-Marie-Tooth disease.
Doctors can't always find the cause of peripheral neuropathy. In one-third of cases, it remains unknown. This makes prescribing treatment difficult. When doctors cannot identify the cause of this condition, they call it idiopathic peripheral neuropathy.
Types of Peripheral Neuropathy
More than 100 types of peripheral neuropathy exist, says the U.S. National Institute of Neurological Disorders and Stroke.
According to one classification, there are three main categories of peripheral neuropathy:
• Motor neuropathy affects motor nerves. The central nervous system uses these nerves to send orders to all the muscles in the body. They allow you to walk, talk, move your fingers, and catch a ball. Damage to motor nerves can cause muscle weakness, cramps, and spasms. It can also make walking or moving your arms difficult.
• Sensory neuropathy affects sensory nerves. They send information from your muscles to your central nervous system. They allow you to sense temperature, touch, and pain. Damage to sensory nerves can cause numbness, tingling, extreme sensitivity to touch or temperature, and even pain.
• Autonomic nerve neuropathy affects autonomic nerves. These control bodily functions like heartbeat, breathing, digestion, sweating, and blood pressure. You can't control most of these functions. Damage to autonomic nerves may cause your heart to beat faster (or slower) or cause you to be unable to sweat (or sweat too much). It may also lead to problems with digestion, urination, and sexual functions.
Here are some examples of peripheral neuropathies.
• Diabetic neuropathy It affects all three groups of nerves (motor, sensory, and anatomic). And it damages nerves throughout the body.
• Alcoholic neuropathy Excessive alcohol use damages the peripheral nerves.
• Guillain-Barré syndrome This is a rare disease in which the body's immune (defense) system attacks the nerves.
• Bell's palsy This disorder affects the nerves and muscles of the face.
• Ulnar neuropathy Its cause is the compression of the ulnar nerve, located in the arm.
• Chemotherapy-induced neuropathy Nerve damage can be a side effect of using chemotherapy drugs to treat cancer.
• Carpal tunnel syndrome Repetitive movements (such as typing on a keyboard) put pressure on the nerve and tendons in the forearm and hand.
Most people with peripheral neuropathy have more than one type at the same time. The term for this condition is polyneuropathy. If you have only one damaged nerve, you have mononeuropathy. Each type of neuropathy has its own set of symptoms.
The symptoms of peripheral neuropathy range from mild to severe. Some can be disabling and even lead to paralysis. Pain may or may not be present. In fact, according to researchers, pain is a symptom of half of all cases of polyneuropathy.
The symptoms may appear suddenly, or take months or years to develop. Their onset depends on the cause of nerve damage. For example, the symptoms of diabetic peripheral neuropathy develop slowly and get worse over time. On the other hand, those of acute peripheral neuropathy develop suddenly.
Peripheral neuropathy symptoms may vary depending on which nerves have suffered damage. But some of the common symptoms of many peripheral neuropathies include the following:
• Tingling, burning, or prickling sensation in the feet, legs, hands, or arms
• Weakness and numbness in the limbs
• Inability to feel that something is too hot or too cold
• Noticing no pain when you step on something sharp
• Burning or freezing sensation in the hands or feet
• Extreme sensitivity to touch
• Extreme sensitivity to heat or cold
• Sharp, shooting pain in the limbs
• Loss of balance
• Difficulty walking
• Poor coordination
• Loss of reflexes
• Muscle twitching
• Loss of mobility
This list of peripheral neuropathy symptoms does not include all the signs of nerve damage. Specific types of peripheral neuropathy may have other symptoms that are not on this list. If you notice any of the above symptoms or others, speak to your doctor.
Who Is More Likely to Develop Peripheral Neuropathy?
Peripheral neuropathy affects between 5 and 8 percent of people in the world.
People of any age can suffer from peripheral neuropathy. But, according to an article in Handbook of Clinical Neurology, older adults are more likely to develop this condition than are younger people.
Also, men are more likely than women to develop almost all types of peripheral neuropathy. There is one exception, though. Carpal tunnel syndrome is more common in women than in men.
Many medical conditions can cause nerve damage. Individuals suffering from a range of conditions may be at a higher risk than others to develop peripheral neuropathy. These include:
• People who have nerve damage from a previous injury or illness
• People with diabetes, immune diseases, vitamin deficiencies, or AIDS
• Alcoholics -- according to German researchers, between 22 and 66 percent of people with chronic alcoholism have peripheral neuropathy
• Cancer patients who had chemotherapy -- between 30 and 40 percent of those who have received chemotherapy drugs develop peripheral neuropathy, says the National Comprehensive Cancer Network
• People who have suffered poisoning from exposure to heavy metals, toxic chemicals, or radiation
If you are one of the people with an increased risk of peripheral neuropathy, go to the doctor for regular check-ups. Also, speak to your physician if you believe you may have peripheral neuropathy symptoms.
Your doctor will examine your symptoms, your posture and coordination, and perform a physical exam. They may ask you about your medical history. Also, you may need to answer questions about your family's medical history. Your answers may be important, because some types of peripheral neuropathy are hereditary (run in the family).
Your doctor will use this information to assess if you have an increased risk of neuropathy. Then, they might check your reflexes, and your ability to feel temperature and pain.
If necessary, your physician will request a neurological examination, blood and urine tests, as well as other medical exams. These will reveal if you have diabetes, hypothyroidism, vitamin deficiencies, or other conditions that can cause peripheral neuropathy.
The outcome of these tests will help your doctor discover whether you have a neuropathy. If you do, they'll try to identify the causes of nerve damage. For this, they might recommend further exams. They may ask for a nerve biopsy (take a sample of nerve tissue to examine), MRI (magnetic resonance imaging) scan, or CT (computed tomography) scan.
As you might have realized, diagnosis of peripheral neuropathy is often difficult. Many diseases can affect your nerves and muscles. That's why your doctor will likely need to collaborate with other specialists to diagnose your condition. So, arm yourself with patience. Be ready to undergo several medical exams before you can receive a diagnosis and treatment for your condition.
The treatment options for peripheral neuropathy depend on its cause. Once your doctor diagnoses your condition, they will be able to recommend the appropriate course of treatment. Follow the treatment your doctor prescribes.
The information in this article gives you an idea about what treatments exist.
Addressing the Cause
The therapy for peripheral neuropathy aims to treat the cause of nerve damage. For example, if the cause is a pinched nerve, the doctors may use surgery to release the nerve. Or, if the cause of your peripheral neuropathy is diabetes, your doctor will aim to control it.
As peripheral nerves have the ability to fix themselves, some of the symptoms may disappear following treatment. Or, they may go away on their own.
Not all nerve damage can be undone, though. In some cases the nerve cell is dead, and no treatment can reverse this. Also, unfortunately, some types of peripheral neuropathy have no known cure. This is the case of inherited peripheral neuropathies. It's also the case of diabetic peripheral neuropathy.
This is a common type of neuropathy in America, affecting about one in two people with diabetes. Diabetic peripheral neuropathy can cause pain, sensory loss, foot sores, and gait instability, reducing the quality of life. Though no known treatment can reverse nerve damage due to diabetes, there are treatments that may improve the symptoms. One example is transcutaneous electrical nerve stimulation. This is a noninvasive intervention (meaning it doesn't require surgery) that might relieve pain.
Reducing the Symptoms
When doctors can't treat the cause of peripheral neuropathy, the treatment may focus on managing symptoms. In other words, doctors will recommend methods to reduce specific symptoms.
Different types of damaged nerve require different therapies.
• For sensory neuropathies, medication might help control chronic pain. Your doctor will recommend appropriate pain-control medication. Examples of drugs for neuropathic pain include steroids, anti-seizure medicines, opioids, and antidepressants.
• For motor neuropathies, doctors may recommend braces, orthopedic shoes, splints, or other mechanical aids. These aim to improve function, and reduce physical disability and pain. They may also allow the nerves to heal.
• For autonomic neuropathies, doctors may recommend how to cope with neuropathic pain. Massage, certain medications, and psychotherapy techniques can help you cope with pain.
Not all people need medication for managing their peripheral neuropathy symptoms. On the one hand, pain is not a symptom in all cases, as mentioned earlier. On the other hand, some kind of neuropathic pain can be mild. Your doctor can show you ways to manage it.
When medication to control pain doesn't work, doctors may recommend surgery. Usually, this works only for mononeuropathy (only one nerve is damaged). For example, pinched nerves usually require surgery. This releases the compression and allows the nerve to heal.
Surgery doesn't usually work for neuropathies that affect more than one nerve.
Other treatments for peripheral neuropathy can help you manage your symptoms and prevent them from getting worse. One example is physical therapy. It includes exercises to improve the body's ability to maintain coordination, agility, and balance -- or proprioception.
Other treatments include occupational therapy, relaxation therapies, guided imagery, biofeedback, and acupuncture.
Managing Peripheral Neuropathy
For some types of peripheral neuropathy there are no therapies. And some neuropathies have no known cause. So, many people have to live with this condition.
Fortunately, not all types of peripheral neuropathy are crippling, and some symptoms are mild. Also, peripheral nerve cells grow throughout your life. This means that some nerves may regenerate. If they do, symptoms might resolve on their own. Not all symptoms lessen or disappear over time, though.
The goal of managing your peripheral neuropathy should be to maintain and restore the function of your peripheral nervous system. Managing peripheral neuropathy involves making healthy lifestyle choices. It also requires taking preventive measures and focusing on restoring function.
Choosing a Healthy Lifestyle
Making healthy lifestyle choices can improve nerve health, as well as helping you cope with the symptoms of neuropathy. Here are some examples of healthy lifestyle choices you can make:
• Maintaining an optimal weight
• Eating a balanced diet
• Avoiding exposure to toxic chemicals and heavy metals
• Not smoking
• Avoiding alcohol
• Using relaxation techniques
Compensating for Loss of Sensation
When you have a neuropathy, you have to do more than lead a healthy lifestyle. Consider taking measures to counteract the loss of sensation that your condition can cause. You need to pay particular attention to your hands and feet. Loss of sensation can make it hard or impossible to notice pain, extreme temperature, or injuries to your hands and feet.
Take measures to prevent injuries that loss of sensation may cause. Here are some of these measures:
• Wear gloves when you handle heavy equipment, work outdoor, or do repairs
• Be extra careful when you use sharp objects
• Avoid extreme temperatures
• Keep your feet and hands warm in cold weather
• Use oven gloves when you handle hot dishes or pans
• Use a water thermometer to check your bath water
• Choose footwear that fits properly
• Ask your doctor if they can recommend therapeutic shoes
Also, if you have problems with balance, there are things you can do to prevent falls. For instance:
• Use a walking cane or another walking device. Speak to your doctor if you need help choosing the right walking aid.
• Sit down when you do some activities you would normally perform standing up (like brushing your teeth).
• Consider installing handrails in your bathroom.