Polyneuropathy: Causes, Symptoms, Diagnosis, Treatment, Risk Factors and Overview

It is a condition in which a patient’s peripheral nerves are damaged.

Polyneuropathy is a “permanent change or malfunction of the nerves “. As we well know, nerves are present throughout the body.

When polyneuropathy develops, it affects the nerves of the skin, the nerves of the muscles, mainly those of the arms, legs, hands and feet, as well as the nerves of the organs in general.

The word polyneuropathy is derived from the roots “Poli” which means many, “neuron” which means nerve and “pathos” which means disease.

Polyneuropathy is a neurological disorder that can occur when peripheral nerves throughout the body malfunction simultaneously.

This can cause sudden, sharp pain or it can be chronic and develop over a longer period of time.

The most common symptoms of polyneuropathy include weakness in the body, loss of sensation in the extremities, the sensations of pins and needles, and also pain in the affected area.

When nerves are damaged, they cannot send regular signals to the brain. However, this condition does not affect the nerves of the brain or spinal column.

Causes of polyneuropathy

The causes of polyneuropathy can be grouped according to the origin into the following types:

Idiopathic causes

In idiopathic polyneuropathy, the cause of the nerve damage is not known.

Acquired causes

Acquired polyneuropathy is polyneuropathy that is caused by an event that occurs outside the body, such as a traumatic injury or infection.

It can also be caused by an underlying condition that is not well treated or causes complications, such as a vitamin deficiency, diabetes, or cancer.

Hereditary causes

Hereditary polyneuropathy is genetically transmitted by one of the parents.

These conditions generally cause slow and gradual damage to the nerves, as in Charcot-Marie-Tooth disease.

There are two main categories of polyneuropathy: acute and chronic.

Acute polyneuropathy

Acute forms occur when the condition occurs suddenly and the symptoms are very severe. This type is common when you have an autoimmune reaction or infection that causes nerve damage.

A disorder such as Guillain-Barré syndrome may be the cause. In acute cases they can often be treated successfully in a short time, and these acute forms can happen due to several different causes.

These include:

  • The use of certain insecticides.
  • Autoimmune disorders in which your body attacks the myelin in nerve cells, such as Guillain-Barré syndrome.
  • The administration of some antibiotics, anticonvulsants and sedatives.
  • Having cancer, especially those that directly affect the nervous system, such as multiple myeloma.
Chronic polyneuropathy

Chronic forms occur when your symptoms last a long time and cannot be treated quickly. This type can be caused by underlying conditions, such as diabetes or kidney failure .

There can be many different causes of chronic polyneuropathy. It is not always easy to discover the cause, and some cases do not have a clear cause.

Chronic forms are often idiopathic, but they can also have causes such as:

  • Alcoholism or drinking a lot of alcohol in general.
  • Diabetes and lack of control over blood sugar levels.
  • Ingestion of certain heavy metals.
  • Nutritional or vitamin deficiencies, especially thiamine or vitamin B-12.
  • Having hypothyroidism .
  • Having kidney failure.
  • Having some cancers, including lung cancer.


The symptoms of polyneuropathy can vary depending on what causes them.

The most common symptoms include:

  • Abnormal sensations of tingling, cold, or heat, known as paresthesia .
  • Presence of sudden sharp pains.
  • Have an abnormal burning or tingling sensation, especially in the feet and hands, known as distal polyneuropathy.
  • Extreme sensitivity to touch, known as allodynia.
  • Present numbness in the affected areas.
  • Weakness in the legs or arms (sometimes due to weak or atrophied muscles).
  • Inability to walk straight, leading to frequent tripping or falling.
  • Difficulty swallowing occurs.

Diagnosis of polyneuropathy

The doctor will likely perform various tests to find out if the patient has polyneuropathy and what is the cause.

A complete physical exam will help the doctor find out which parts of the body are most affected by damage and pain to your nerves.

A physical exam can also help the doctor find any weak or atrophied muscles that may have been affected by nerve damage.

Your doctor may also do electrical tests of nerves and muscles to see the extent of nerve damage.

A blood test, urine samples, and biopsy of the area affected by nerve damage (sometimes the nerves as well) will also help the doctor find out what is the cause and extent of the polyneuropathy. Other tests may be necessary if the doctor suspects an underlying condition.

A lumbar puncture can help determine if the patient’s protein and white blood cell levels are abnormal.

Abnormal results may mean that you have conditions such as Guillain-Barré syndrome.


Treatment for polyneuropathy depends on the condition that caused it. It can also depend on where the symptoms are felt on the body.

In some cases, the doctor may administer pain relievers to help control pain and discomfort caused by nerve damage. These can include non-steroidal anti-inflammatory drugs.

Among the treatments for polyneuropathy we have:

  • Changes in lifestyle. Making lifestyle changes can help treat polyneuropathy.
  • Drinking less alcohol or avoiding certain repetitive tasks can help relieve symptoms.
  • If a toxin or chemical in the environment is causing your polyneuropathy, your doctor may urge you to find a way to limit your exposure to it.

Traumatic injuries

When you have polyneuropathy after a traumatic injury, your doctor may recommend physical therapy. This can help you regain full control of your body.

You can also learn to manage pain and nerve sensations that may have been caused by the injury.

Autoimmune conditions

If an autoimmune condition is causing polyneuropathy in the patient, the doctor may suggest different treatments or therapies.

These may include:

  • Use of corticosteroids.
  • Immunoglobulin injected intravenously (directly into the veins).
  • Plasma exchange, which removes toxins present in the blood.


If diabetes is causing polyneuropathy, your doctor will likely recommend a treatment plan to help control your blood sugar levels.

This type of treatment plan often includes oral medications or self-administered insulin injections.

In rare cases of type 1 diabetes, your doctor may suggest surgery to transplant insulin-producing cells (known as islet cells) from a donor pancreas to help your body make and release more insulin.

This is a major surgery and will probably only be recommended if all other treatments fail.


If cancer cells or cancerous tumors are causing the polyneuropathy, the doctor may recommend surgery to remove the cells or tumors.

Chemotherapy can help kill tumors or cancer cells that are putting pressure on nerves.

Risk factors for polyneuropathy

The general health of the patient may reveal their risk factors for polyneuropathy.

Common risk factors include:

  • Diabetes mellitus.
  • Kidney or liver diseases.
  • Autoimmune disorders.
  • The alcoholism.
  • Infections, including HIV, shingles, and Lyme disease.
  • Using certain parts of the body repeatedly (such as for industrial work), also called a repetitive motion injury.


You can help reduce nerve damage by detecting certain conditions early.

In this way, the patient can receive treatment before pain or discomfort becomes difficult to control.

If the symptoms of polyneuropathy, especially after a major injury, are noticeable, a doctor should be consulted as soon as possible.

Once it is determined whether the patient has any conditions that may be causing the polyneuropathy, early treatment of symptoms is the best way to prevent the polyneuropathy from reaching levels that cause negative conditions in the patient’s life.