What Causes Peripheral Neuropathy? 20 Common Causes Explained

One of the first questions many people ask after being diagnosed with peripheral neuropathy is:

“What caused it?”

It is a sensible question, but unfortunately the answer is not always straightforward.
Peripheral neuropathy is not a single disease. It is a term used to describe damage to the peripheral nerves—the nerves that carry messages between the brain, spinal cord, and the rest of the body.
Many different medical conditions, medications, injuries, and lifestyle factors can damage these nerves. Sometimes the cause can be identified quickly. In other cases, even after extensive testing, no clear cause is found.
The good news is that identifying the underlying cause can sometimes help slow progression, improve symptoms, or prevent further nerve damage.
In this guide, we will look at 20 of the most common causes of peripheral neuropathy and explain them in plain English.

Why Finding the Cause Matters

Finding the cause is important because treatment often focuses on addressing the underlying problem.
For example:

• Better blood sugar control may help diabetic neuropathy.
• Correcting vitamin deficiencies may improve symptoms.
• Changing medications may prevent further nerve damage.
• Treating autoimmune conditions may slow progression.

Unfortunately, not every cause can be reversed, but understanding what is happening gives doctors the best chance of managing the condition effectively.

1. Diabetes

Diabetes is the most common cause of peripheral neuropathy worldwide.
High blood sugar levels over time can damage nerves and the small blood vessels that supply them.
Symptoms often begin in the feet and gradually move upward.
Common signs include:

• Numbness
• Tingling
• Burning sensations
• Reduced sensation
• Balance problems

Good diabetes management can help reduce the risk of progression.

2. Prediabetes

Many people are surprised to learn that neuropathy can develop even before diabetes is formally diagnosed.
Prediabetes occurs when blood sugar levels are higher than normal but not yet high enough to be classified as diabetes.
Some people develop nerve symptoms during this stage, particularly burning feet or tingling sensations.

3. Alcohol Misuse

Long-term excessive alcohol consumption can damage nerves directly.
Alcohol can also interfere with the body’s ability to absorb important nutrients such as vitamin B1, also known as thiamine, increasing the risk of nerve damage.
Symptoms often affect the feet and legs first.

4. Vitamin B12 Deficiency

Vitamin B12 plays an essential role in maintaining healthy nerves.
Low levels can lead to:

• Numbness
• Tingling
• Balance difficulties
• Weakness
• Memory problems

Fortunately, B12 deficiency can often be treated if detected early.

5. Other Vitamin Deficiencies

Several other vitamins are important for nerve health.
These include:

• Vitamin B1, also known as thiamine
• Vitamin B6
• Vitamin E
• Folate

Poor diet, digestive disorders, or certain medications can sometimes lead to deficiencies.

6. Autoimmune Diseases

Autoimmune conditions occur when the immune system mistakenly attacks healthy tissues.
Some autoimmune diseases can target nerves directly.
Examples include:

• Rheumatoid arthritis
• Lupus
• Sjögren’s syndrome
• Vasculitis

Treatment usually focuses on controlling the immune response.

7. Chronic Kidney Disease

When the kidneys do not function properly, waste products can build up in the bloodstream.
These toxins may damage nerves over time.
Neuropathy associated with kidney disease often affects the legs and feet.

8. Liver Disease

The liver performs many important functions, including filtering toxins.
When liver function is impaired, nerve damage can sometimes occur as a secondary complication.

9. Thyroid Disorders

An underactive thyroid, known as hypothyroidism, can contribute to peripheral neuropathy.
People may experience:

• Numbness
• Tingling
• Muscle weakness
• Fatigue

Treating the thyroid condition may help improve symptoms.

10. Certain Medications

Some medications can cause nerve damage as a side effect.
Examples include certain:

• Chemotherapy drugs
• Antibiotics
• Heart medications
• Anti-seizure medications

This does not mean people should stop prescribed medicines without medical advice.
If concerns arise, discuss them with a healthcare professional.

11. Chemotherapy-Induced Neuropathy

Chemotherapy deserves special mention because it is a well-known cause of nerve damage.
Some cancer treatments can affect sensory nerves, leading to:

• Tingling
• Numbness
• Pain
• Sensitivity to touch

Symptoms may improve after treatment, but sometimes they can persist.

12. Inherited Neuropathies

Some neuropathies run in families.
One example is:

• Charcot-Marie-Tooth disease

These conditions are caused by genetic changes that affect nerve function.
Symptoms often develop gradually over many years.

13. Infections

Certain infections can damage nerves directly or trigger immune reactions that affect nerves.
Examples include:

• Shingles
• Lyme disease
• HIV
• Hepatitis B
• Hepatitis C

In some cases, treating the infection can help reduce further nerve damage.

14. Physical Injury or Trauma

Nerves can be damaged by:

• Accidents
• Falls
• Sports injuries
• Surgery

Sometimes a single nerve is affected, while in other cases multiple nerves may become involved.

15. Repetitive Pressure on Nerves

Repeated pressure can compress nerves and interfere with their function.
Common examples include:

• Carpal tunnel syndrome
• Ulnar nerve compression at the elbow

These conditions often cause numbness, tingling, or weakness in specific areas.

16. Exposure to Toxins

Various environmental and industrial toxins have been linked to neuropathy.
Examples include:

• Lead
• Mercury
• Arsenic
• Certain industrial chemicals

Occupational exposure can occasionally be an important clue during diagnosis.

17. Cancer

In some cases, cancer itself can affect nerves.
This may happen because:

• Tumours press on nerves
• The immune system reacts abnormally
• Cancer-related chemicals affect nerve tissue

Neuropathy can occasionally be one of the first signs that prompts further investigation.

18. Monoclonal Gammopathy (MGUS)

Monoclonal Gammopathy of Undetermined Significance, often shortened to MGUS, is a condition involving abnormal proteins in the blood.
Many people with MGUS never develop symptoms.
However, in some individuals these proteins may contribute to nerve damage.
MGUS becomes more common as people get older.

19. Amyloidosis

Amyloidosis is a rare condition in which abnormal proteins accumulate in tissues and organs.
These deposits can damage nerves and cause symptoms such as:

• Numbness
• Tingling
• Weakness
• Balance difficulties

Diagnosis often requires specialist testing.

20. Idiopathic Neuropathy

Sometimes no cause is found.
This is called idiopathic peripheral neuropathy.
For many people, this can be one of the most frustrating outcomes of the diagnostic process.
You may undergo blood tests, scans, nerve conduction studies, and specialist assessments only to hear:

“We cannot find a clear reason.”

Although this can feel disappointing, it is actually quite common.
Many people live with idiopathic neuropathy, including those diagnosed with conditions such as Idiopathic Sensory Motor Axonal Polyneuropathy.
Doctors continue to research possible causes that may not yet be fully understood.

Can Someone Have More Than One Cause?

Yes.
In fact, many people have several risk factors.
For example, a person may have:

• Prediabetes
• A vitamin deficiency
• Mild alcohol-related nerve damage

All at the same time.
This can make diagnosis more challenging and explains why doctors often order multiple tests.

What Tests Help Identify the Cause?

Doctors may use:

• Medical history
• Physical examination
• Blood tests
• Vitamin level checks
• Diabetes screening
• Thyroid testing
• Kidney and liver function tests
• Nerve conduction studies
• Electromyography, also known as EMG
• Genetic testing in some cases
• Imaging scans when appropriate

The goal is to identify any treatable cause whenever possible.

A Word from John

“One of the hardest things about neuropathy can be not knowing why it happened. Many of us spend months—or even years—looking for answers. If doctors have not found a cause, you are certainly not alone. While understanding the reason can help, learning how to manage the condition day by day is often just as important.”

Key Takeaways

• Peripheral neuropathy has many possible causes.
• Diabetes remains the most common cause worldwide.
• Vitamin deficiencies, autoimmune diseases, medications, infections, and injuries can all contribute.
• Some people have several contributing factors.
• In many cases, no clear cause is found despite extensive testing.
• Identifying a treatable cause can sometimes help slow progression and improve symptoms.

Next Article in the Learning Path

Idiopathic Neuropathy: When Doctors Cannot Find a Cause

Medical Disclaimer

This article is for educational and informational purposes only and should not be considered medical advice. Always consult your doctor, neurologist, or healthcare professional regarding symptoms, diagnosis, treatment options, or changes to your healthcare plan. Medical knowledge changes over time, and treatment decisions should always be based on your individual circumstances and professional medical guidance.

If you experience new symptoms, worsening symptoms, falls, sudden weakness, or concerns about your health, seek professional medical advice promptly.