What Is Neuropathy?

Many people are familiar with that uncomfortable "pins and needles" feeling that can happen when you sit in a particular position for too long.  But some people experience those symptoms all the time.  It is called neuropathy, also known as peripheral neuropathy.  Neuropathy happens when a nerve or group of nerves does not function normally.  It can have many different causes, including diabetes, trauma, nerve injury, illness, or medications.

What Is Neuropathy?
By Pierre Mouchette | Bits-n-Pieces

What is peripheral neuropathy?
The word neuropathy means nerve damage or dysfunction.  Our nervous system has two parts: the central nervous system (the brain and spinal cord) and the peripheral nervous system (all the other nerves throughout the body).
Peripheral neuropathy refers to damage to the peripheral nerves, the nerves outside the brain, and the spinal cord in the rest of your body.  Neuropathy can be related to problems in the central nervous system, but it can also happen when the brain and spinal cord function normally.
There are three types of peripheral nerves:

• Sensory nerves help you feel.
• Motor nerves help you move.
• Autonomic nerves perform automatic functions like sweating, breathing, and digesting food.

Neuropathy can affect any of these nerve types, and in some cases, it can affect just one nerve, and in other cases, it can affect several nerves.  The type and number of nerves involved affect what kind of symptoms you have.  Typically, neuropathy is a long-term condition.  But it also depends on the underlying cause.
 
What causes peripheral neuropathy?
The most common cause of neuropathy in the US is diabetes, with as many as 60 to 70 percent of people with diabetes having neuropathy.  However, diabetes is not the only cause of neuropathy.  Other causes include:

• Genetic disorders - These are rare causes.
  
  
• Illness - Vascular disease, autoimmune conditions, infections, vitamin deficiencies, alcohol misuse, kidney disease, and cancer can all cause neuropathies.
  
  
• Medications - Chemotherapy, blood pressure medications, and antibiotics are common offenders.
  
  
• Trauma - Accidents, cuts, and broken bones can directly injure a nerve.  It can also happen during medical procedures like surgery.

 
What causes neuropathy in the feet?
When people have neuropathy, it is expected to experience it in the feet.  Certain conditions are known for causing neuropathy in the feet in particular:
Diabetes - People with diabetes and neuropathy are most likely to experience symptoms in their legs and feet.
Vascular disease - When problems with the blood vessels cause neuropathy, they often affect the feet first.  It is because they are the farthest body part from the heart.
Charcot-Marie-Tooth disease (CMT) is an inherited condition that commonly causes nerve damage in the feet.
Peroneal nerve palsy - the peroneal nerve is located outside the knee and in the lower leg.  Because of its location in the leg, it is vulnerable to compression or injury.  When that happens, it leads to something called "foot drop," when it becomes difficult for a person to lift their foot.
 
What are the symptoms of peripheral neuropathy?
The symptoms of peripheral neuropathy may feel different for different people.  It is because the symptoms depend on the type, the number, and the location of the peripheral nerves affected.
Common symptoms include:

• Loss of pain or sensation
• Muscle weakness
• Numbness, tingling, or a pins-and-needles sensation
• Painful sensitivity to touch
• Loss of muscle mass (sometimes called "muscle wasting")

Sometimes, these symptoms can be worse at night.  Some people with peripheral neuropathy may also experience other types of neuropathies, such as those associated with the autonomic nervous system.  These symptoms can be more subtle but include:

• Digestive symptoms
• Dizziness and loss of balance
• Emotional changes
• Heat intolerance

 
How is peripheral neuropathy diagnosed?
Peripheral neuropathy is often diagnosed based on a combination of symptoms, a history of symptoms, and a physical exam.  Sometimes, tests to evaluate for other conditions may be helpful.  These tests may include blood work, spinal fluid tests, and imaging in some cases.
Some tests are specific to nerve function:

• A neurodiagnostic skin biopsy can help diagnose peripheral neuropathy of tiny nerve fibers.
• Electromyography (EMG) tests look at both nerve and muscle function.  It can help determine if weakness is due to a problem with the nerve or a problem with the muscle.
• Nerve conduction studies help identify which nerves are damaged.

 
Can I test for neuropathy at home?
Yes, you can test for neuropathy in your feet at home using what is known as the Ipswich test.  It is a simple test that does not require any special equipment and is as follows:

1. Close your eyes.
2. Ask a family member to tap gently and quickly the first, third, and fifth toes of each of your feet using their index finger.

If you cannot feel them touching your foot, you may have neuropathy.  But keep in mind that this is a screening test.  Following up with your provider for the additional testing mentioned above is best.
 
What are the treatments for peripheral neuropathy?
Treatment for peripheral neuropathy usually depends on its cause.  When an injury causes neuropathy, rehabilitation may help improve symptoms.  Orthopedic devices, like braces or splints, may help maintain a position that reduces pressure on a nerve and improves pain, numbness, or weakness.  Surgery can also help alleviate symptoms caused by nerve damage or compression.
In the case of medication-related neuropathy, stopping the medication often improves symptoms.  The same is true for neuropathy caused by diabetes or autoimmune disease.  Treating the underlying condition may not cure the condition, but it can help improve symptoms and prevent neuropathy from becoming worse.
Several types of medications can help treat the pain associated with neuropathy.  Some of these medications are known to treat neuropathic pain, which means pain related to nerve damage.  Examples of these medications include:

• Antidepressants
• Gabapentin (Neurontin)
• Local anesthetics
• Pregabalin (Lyrica)
• Seizure medications

There are also some non-medication options for treating peripheral neuropathy, such as acupuncture and transcutaneous electrical nerve stimulation (TENS).  These treatments may be helpful for some people, but more research is needed, particularly for TENS therapy.
 
Is neuropathy curable?
In most cases, there is no cure for neuropathy.  However, many treatments described above can help improve the discomfort neuropathy may cause.  If the neuropathy is due to an underlying condition, treating that condition can often prevent it from worsening.
 
What are the long-term risks of peripheral neuropathy?
If the underlying cause of neuropathy is not treated, it may cause some long-term problems:

• Neuropathy involving a motor nerve can cause muscle waste and weakness.  Weakness can make it challenging to do your usual daily activities and increase your risk of falling.
  
  
• Neuropathy of a sensory nerve can cause long-term numbness or inability to feel pain or discomfort.  It can make it difficult for you to know if you have accidentally hurt yourself.  In serious cases, the injury and infection can become severe and even require surgery.

 
What can you do to prevent peripheral neuropathy?
The best ways to prevent peripheral neuropathy are to:

• Treat any medical conditions that may cause nerve damage, like diabetes.
  
  
• Avoid taking medications that are known to cause neuropathy unless necessary.
  
  
• Talk to your healthcare team about the risks of nerve injury from a medical procedure before deciding to have one.

 
Is there anything that makes peripheral neuropathy worse?
Some factors may make peripheral neuropathy worse like:
Alcohol - some peripheral neuropathies are caused by alcohol use.
Diet - eating a diet rich in saturated fat (think greasy or fried foods) may cause worsened inflammation throughout the body and could worsen neuropathy.
Smoking - smoking makes the blood vessels smaller.  It makes it harder for the blood to carry nutrients and oxygen to the nerves in your arms and legs, which may worsen neuropathy.
Stress - chronic stress may make neuropathy hurt more.
Vitamin deficiencies - certain vitamin deficiencies have been reported to make neuropathies worse.  Your provider can help test your vitamin levels to see if a supplement may be good for you.