Neuropathy is very common. It is estimated that about 25% of Americans will be affected. Yet more than a third don’t know what caused it. If you are one of them, you may be wondering what causes peripheral neuropathy. 

Neuropathy is a common condition that results from damage to any of the nerves outside of the brain and spinal cord. 

It isn’t a lone disease. At the root, there is always a cause — some other condition or problem of sorts. In fact, there are over 100 known causes ¹. And the phrase “known cause” is used because there are still many more causes of neuropathy that are more or less unknown. 

When the cause of nerve damage cannot be traced, it’s given the term idiopathic, which literally just means “unknown cause,” and is used to describe about a third of all cases ².

Understanding what can cause nerve damage can help you better understand the sensitive nature of nerves and get you thinking about some of the ways they may have become damaged, or are continuing to be damaged further.

And more importantly, ways you can begin to eliminate what causes nerve damage, where possible.

The cause of peripheral neuropathy for you may or may not be attributed to one specific cause. Rather, it may be a combination of factors that have compromised the health of your nervous system. 

Chronic Inflammation: The Common Factor

One common factor to nearly all causes of neuropathy is chronic inflammation. In fact, chronic inflammation is now being recognized as the underlying common denominator of nearly all modern diseases ³.

Inflammation is a normal response of the body’s immune and healing systems. It helps protect against disease and infection, and is responsible for healing the body when damage takes place.

When chronic, inflammation in the body can cause or accelerate disease, and prohibit healing. 

Next you’ll get an overview of known causes broken into two distinct categories: biological and mechanical. These are not intended to be complete lists (and remember not all causes have been identified).

However, they illustrate the complexity and difficulty for determining direct causes of nerve damage.  As well as show how peripheral neuropathy can develop as a result of multiple risk factors.

Biological Causes of Neuropathy

The most common types of neuropathy are the biologically-caused, if for no other reason than the range of potential ways in which the body can become diseased. 

Biological causes of neuropathy are those that result from diseases.

Keeping current with routine physical screenings is important to identify and manage diseases early to avoid or minimize their damaging effects.

Diseases That May Cause Neuropathy

• Diabetes, prediabetes, metabolic syndrome ^{4 5}
• Kidney disease ⁶
• Liver disease ⁷
• Thyroid disease ⁸
• Bacterial or viral infections ⁹
• Alcoholism ¹⁰
• Atherosclerosis ¹¹
• Some cancers ¹²
• Sarcoidosis ¹³
• Guillain-Barre syndrome ¹⁴
• Rheumatoid arthritis ¹⁵
• Sogren’s syndrome ¹⁶
• Chronic venous insufficiency ¹⁸
• Vasculitis ^{19 20}
• Cytomegalovirus ²¹
• Gastric bypass surgery ²²
• Lupus ²³
• Lyme disease ²⁴
• Peripheral artery disease ²⁵
• Heart diseases ²⁶
• Gut infections ^{27 28}
• Fabry’s Disease ²⁹
• Nutritional deficiencies ³⁰
• Vitamin toxicity ³¹
• HIV ³²
• Excessive weight ³³
• Post-surgical inflammation ³⁴
• Shingles ³⁵
• Tumors ³⁷
• Connective tissue diseases ³⁸
• Vitamin deficiencies ⁴⁰
• Charcot-Marie-Tooth disease ⁴¹
• Chronic inflammatory demyelinating polyradiculoneuropathy ⁴²
• Critical illness ⁴³

Mechanical Causes of Neuropathy

Mechanical causes of neuropathy involve the body being acted upon by an outside force or structural dysfunction. This typically means injury, constriction, compression, or other trauma that can result in nerve damage ⁴⁴. 

Misaligned joints causing pinched nerves can result in conditions that may lead to long-term nerve damage if left untreated. Surgery can be another type of mechanical process that can cause peripheral neuropathy due to the cutting of nerves or post-surgical inflammation.

Examples of mechanical causes of peripheral neuropathy include:

• Brachial plexus syndrome
• Broken bone
• Bunion
• Carpal tunnel syndrome
• Herniated discs
• Joint trauma
• Morton’s neuroma
• Pinched (entrapped, compressed) nerves
• Piriformis syndrome
• Sciatica
• Stenosis
• Slipped disc
• Spinal surgery
• Spinal tumor
• Surgical damage ⁴⁵

Toxic Causes of Neuropathy

Chemicals, toxins, and poisons causing nerve damage are often referred to as toxic neuropathy 46. We encounter these nerve-damaging toxins in the form of pollutants in our environment, such as chemicals in the products we use in our homes and toiletries, chemicals we consume through foods, smoking, and even the medications we take. 

The way toxins affect the nervous system is by causing a “dying back” of the nerve cells (neurons) that have the longest nerve fibers (axons) ^{47 48}. 

Because the longest, and therefore most fragile, nerve fibers extend to the toes and fingers, symptoms often appear in these parts of your body first. As the nerve damage progresses, symptoms can move toward the central body.

Diseases of the liver and kidneys reduce your body’s ability to filter toxins, making the impact of toxic exposure more threatening. Be sure you are current on routine liver and kidney screenings.

Environmental Toxins that May Cause Neuropathy

Below are some of the more common toxins we encounter regularly:

• Alcohol ^{49 50}
• Smoke ^{51 52}
• Vitamin toxicity ⁵³
• Indoor mold and mycotoxins ⁵⁴
• Arsenic (water, soil, contaminated foods) ^{55 56}
• Excitotoxins, like MSG and aspartame ^{57 58 59}
• Pesticides ^{60 61}
• Acrylamide ⁶²
• Heavy metals ^{63 64 65} (in some fish, contaminated soil)
• Thallium ⁶⁶ (in contaminated food and water, cigarettes)

Medications That May Cause Neuropathy

There are many medications that carry nerve damage warnings. Some of which are elective, such as acne medications, but others are necessary life-saving drugs, such as those for cancer. 

If you are taking a prescription that you are concerned about, do not stop the medication on your own. Talk to your doctor about your concerns. In some cases, there are alternatives.

The following medications with peripheral nerve damage warnings are combined from these resources:

• Cleveland Clinic
• Foundation for Peripheral Neuropathy
• National Institutes of Health

Used for High Cholesterol

• Altocor (lovastatin)
• Crestor (rosuvastatin)
• Lescol (fluvastatin)
• Lipex (simvastatin)
• Lipitor (atorvastatin)
• Livalo (pitavastatin)
• Pravachol (pravastatin)

Used for Blood Pressure

• Amiodarone
• Captopril
• Enalapril
• Flecainide
• Hydralazine
• Perhexiline

Used for Autoimmune Disorders

• Arava (leflunomide)
• Chloroquine
• Enbrel (etanercept)
• Golimumab (etanercept)
• hydroxychloroquine
• Infiximab (etanercept)
• Remicade (infliximab)

Used for Infections

• Aczone (dapsone)
• Chloramphemicol
• Chloroquine
• Cipro (ciprofloxacin)
• Ethambutol
• Flagyl (metronidazole)
• Isoniazid
• Metronidazole
• Nitrofurantoin
• Savudine
• Suramin
• Thalidomide
• Videx (didanosine)

Used for Rheumatic Diseases

• Allopurinol
• Colchicine
• Etanercept
• Gold
• Indomethacin

Used for Cancer

• Abraxane (paclitaxel)
• Cisplatin
• docetaxel
• Matulane (procarbazine)
• Misonidazole
• paclitaxel
• Platinol (cisplatin)
• Revlimid (lenalidomide)
• Suramin
• vinblastine
• vincristine

Drugs to Treat Seizures

• Carbamazepine
• Dilantin
• Phenytoin
• Phenobarbital

Anti-Alcohol Drugs

• Disulfiram

Drugs to Fight HIV/AIDS

• Emtriva (emtricitabine)
• Truvada (tenofovir and emtricitabine)
• Videx (didanosine)
• Zerit (stavudine)

Other

• Colchicine (used to treat gout)
• Arsenic
• Gold
• Lithium

Next Steps

The best treatment is prevention ⁶⁷. Understanding what causes neuropathy can help to avoid nerve damage or to minimize the damage and symptoms once symptoms have started. Work with your doctor to manage underlying conditions. 

Self-care strategies that reduce chronic inflammation and improve general health is universally recommended for all cases of neuropathy, despite the cause.