Peripheral neuropathy results from damage to the body’s peripheral nerves. As these nerves deteriorate, they are less able to communicate with the muscles, organs and tissues of the body.

Some peripheral neuropathies are inherited (e.g., Charcot-Marie-Tooth disease, Friedreich’s ataxia), while many others are acquired later in life. Inherited neuropathies may cause symptoms early in life, or may not appear until later. Inherited neuropathies that appear during infancy are more likely to be severe than those that appear in young adulthood. 

There are many sources of acquired neuropathy. Physical injury is the most common source of damage to nerves. Sources of such injuries include car accidents, falls and athletic injuries. Less severe injuries, such as herniated discs and broken bones, also can damage nerves. Physical injury can lead to crushed, compressed, stretched or severed nerves. Prolonged immobility can also pressure and damage peripheral nerves.

Many different types of systemic diseases also can cause peripheral neuropathy. Systemic diseases affect the entire body. Examples include:

• Metabolic and endocrine disorders. These include diseases that impair the body's ability to transform nutrients into energy, process waste products, or manufacture substances that are part of living tissue. Diabetes mellitus, a common metabolic disorder, is a leading cause of peripheral neuropathy in the United States. About one-third of all cases of peripheral neuropathy are caused by diabetes, according to The Neurological Association. Approximately half of all people with diabetes develop nerve damage, according to the National Institutes of Health (NIH).
  
  
• Autoimmune disorders. These conditions cause a person’s immune system to attack the body’s tissues. Conditions such as lupus and rheumatoid arthritis are types of autoimmune disorders.
  
  
• Cancers and benign tumors. These conditions can either infiltrate nerve fibers or place damaging pressure upon the fibers.
  
  
• Kidney and liver disorders.  A majority of patients who require dialysis because of kidney failure develop polyneuropathy, according to the NIH.
  
  
• Vitamin deficiencies. Vitamins E, B1, B6, B9 (folate), B12, and niacin are essential to healthy nerve function. A deficiency in any of these vitamins may lead to nerve damage. An excess of vitamin B6 may also lead to a peripheral neuropathy.
  
  
• Toxins. People exposed to heavy metals (arsenic, lead, mercury, thallium), industrial drugs or environmental toxins often develop neuropathy. Certain medications (e.g., anticancer drugs, anticonvulsants, antiviral agents, antibiotics) also can cause neuropathy when used too long.
  
  
• Alcoholism. Some experts believe that excessive alcohol consumption can lead to a condition called alcoholic neuropathy.
  
  
• Repetitive movements. Often results in entrapment neuropathies, in which the nerves are compressed. This type of injury is more common in pregnancy, when fluid retention and weight gain constrict nerve passageways.
  
  
• Infectious or inflammatory conditions. Viral and bacterial infections and inflammatory disorders can damage nerve tissues. Some examples include:
  
  
• • Cytomegalovirus (CMV)
    
    
  • Diphtheria
    
    
  • Epstein-Barr virus (mononucleosis)
    
    
  • Guillain-Barré syndrome
    
    
  • Herpes simplex virus
    
    
  • Shingles (Varicella-zoster virus)
    
    
  • Human immunodeficiency virus (HIV)
    
    
  • Leprosy
    
    
  • Lyme disease
    
    
• Connective tissue disorders and chronic inflammation. Inflammation of the protective tissues around nerves can spread into the nerves themselves.  Chronic inflammation destroys connective tissue, leading to compression injuries and infections involving nerve fibers.
  
  
• Vascular damage and blood diseases. These conditions can hamper oxygen supply, leading to damage or death of nerve tissues.  Blood vessel inflammation (vasculitis) causes vessel walls to harden, thicken and develop scar tissue. This impedes blood flow.
  
  
• Hormonal imbalances. Underproduction of thyroid hormones slows metabolism, while overproduction of growth hormones can lead to acromegaly (abnormal enlargement of many parts of the skeleton), causing nerves to become entrapped in joints.

Despite the numerous factors and conditions that are known to cause peripheral neuropathy, in approximately one-third of peripheral neuropathy cases the cause remains unknown, according to The Neuropathy Association. Peripheral neuropathy with no known cause is sometimes referred to as being “idiopathic.”