What is Peripheral Neuropathy?

Any health condition that negatively affects the nerves located outside the brain and spinal cord is known as peripheral neuropathy. Therefore, there are multiple reasons that may cause this condition, including infections, trauma, inherited disorders, and others. While multiple forms of peripheral neuropathy are treatable, their severity can vary from one person to another.

In general, the name of this disorder is an umbrella term used to describe nerve disorders that impact a specific subdivision of the nervous system. However, it can affect any part of the body, which means the symptoms that occur are also different among people who experience it.

Furthermore, the term “peripheral” comes from a Greek word that means “around”. In such cases, it means outside or away from the central nervous system. The second term, “neuropathy,” combines two words: neuro (from Greek, meaning “neuron”) and pathy (from Greek, meaning “condition” or “affliction”). Generally, the nervous system consists of two parts: the central nervous system (the brain and spinal cord) and the peripheral nervous system (the rest of the nerves in the body).

Peripheral neuropathy is a common disorder that affects about 2.4% of the world’s population. In people over 45 years old, it affects between 5% and 7%.

How Does Peripheral Neuropathy Affect My Body?

However, to understand more about this condition, you should know more about neurons (a little structure that makes up a nerve). So, neurons are involved in sending and relaying signals through the nervous system using electrical and chemical signals. Moreover, each neuron consists of the following parts. Examples include:

Cell body – This is the primary part of a neuron.
Axon – It is an arm-like part that often extends outward from the cell body. An axon also has finger-like extensions where the electrical signals are converted into chemical ones. Furthermore, these extensions are sometimes called synapses.
Dendrites – These are small, branch-like extensions on the cell body. They are responsible for receiving chemical signals from synapses and other neurons.
Myelin – This is a nerve protective layer made up of fatty chemical compounds.

Additionally, peripheral neuropathy occurs in two primary ways. These include:

Demyelinating neuropathy – In such cases, the protective layer of a nerve (myelin) is damaged or is not formed properly. Therefore, it negatively affects the signals that travel between the neurons.
Axonal degeneration – This type of peripheral neuropathy affects the axon and causes it to die. Thus, the longer a neuron is, the worse the effect caused by this condition. That’s why axonal degeneration tends to affect the legs and feet, because they are farthest from the spinal cord and rely on connections using these neurons. Furthermore, most people develop axonal degeneration.

Symptoms

Usually, people experience different symptoms because this disorder can affect different parts of the body. Hence, doctors have divided symptoms into several types. These include motor, sensory, and autonomic.

Motor Symptoms

For example:

Muscle weakness and paralysis – These symptoms may occur due to nerve deterioration that is connected to the muscles. People with paralysis may find it difficult to move their toes and experience hand weakness.
Muscle atrophy – The muscles can shrink in size once they lose the nerve connection. Usually, it affects the feet, lower legs, and hands.
Uncontrollable muscle movements – When the nerves connected to the muscles lose the connection with the brain, it may lead to cramps and involuntary movements.

Sensory Symptoms

Normally, the peripheral nerves convert the information of the outside world into nerve signals that are sent to the brain. It helps you understand what happens around you. When peripheral neuropathy affects these nerves, you may experience the following symptoms. Check below some examples:

Numbness and tingling – These symptoms occur when the disorder affects the nerves that carry signals to the brain.
Imbalance – In normal circumstances, people are not aware that the nerves carry sensations that their brain uses to keep track of the location of the hands and feet. These sensations are essential for balance and coordination.
Pain – Damage to the nerves can make nerves send pain signals to the brain differently. As a result, you may experience a more intense pain, or it may occur too easily.

Autonomic Symptoms

In general, our bodies have multiple autonomic processes. It means some automatic functions that occur without thinking or being aware of them. These include blood pressure, digestion, sweating, and others. Problems with nerves that control these autonomic functions may cause the following symptoms. Examples include:

Changes in the blood pressure – When the peripheral neuropathy damages the nerves that control blood pressure, you may experience sudden drops or increases in the blood pressure and heart rate.
Sweating – This symptom often appears when the nerves that control sweating are damaged. As a result, it can make you sweat too much or not enough, which may cause excessive sweating after eating, scaling on your feet, and other issues.
Bladder and intestine problems – These organs in the body are controlled by the body without thinking about them. If you develop nerve damage, it may lead to constipation or diarrhea. Sometimes, it can also affect the bladder.
Sexual dysfunction – Sexual arousal is also controlled by the autonomic nervous system. Anything that damages these nerves can cause sexual dysfunction.
Other symptoms – Certain autonomic changes can also cause skin color changes, swelling, specific changes in the pupils of the eyes, and vision problems (such as blurred vision).

If any of the previous symptoms occur, immediately see a doctor to confirm or rule out peripheral neuropathy.

Causes

This health condition can occur due to multiple reasons. Check some of them below:

Type 2 diabetes – This disorder is one of the most common causes of peripheral neuropathy, especially if it is left untreated. Damage to the nerves occurs because of blood sugar levels that are too high for long periods. It is also one reason why people with type 2 diabetes lose feeling in their feet and lower legs.
Alcohol use disorder – Misuse of alcoholic beverages, especially for a long time, can also cause damage to the nerves. In general, this disorder is another common cause of peripheral neuropathy.
Vitamin and nutritional deficiencies – Damage to the nerves may occur due to reduced levels of vitamins in the body. These include vitamins B1, B6, B9, B12, B9 (folic acid), and E. However, high levels of vitamin B6 may also cause peripheral neuropathy.
Autoimmune and inflammatory disorders – There are some conditions that may also lead to peripheral neuropathy. These include chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain-Barré syndrome, lupus, rheumatoid arthritis, Sjogren syndrome, vasculitis, and others.
Medicines and toxins – Sometimes, people may develop peripheral neuropathy due to certain medicines (such as chemotherapy drugs, antibiotics, and medicines used to treat arrhythmia and gout) or prolonged exposure to certain heavy metals and industrial chemicals.
Tumors – Damage to the peripheral nervous system can also occur due to benign (noncancerous) and malignant (cancerous) tumors.
Genetic diseases – This group of disorders is often inherited from biological parents during pregnancy. Some of them can also cause peripheral neuropathy. These include Charcot-Marie-Tooth disease, amyloidosis, Fabry disease, and others.
Infections – Some viral and bacterial infections can cause damage to the peripheral nervous system. For example, Lyme disease, HIV infection, shingles, and others.

Other Causes

Hansen disease (also known as leprosy) – This disease rarely occurs in industrialized countries, but it can cause damage to the nerves. However, leprosy is a common cause of peripheral neuropathy in developing countries worldwide.
Trauma and surgery – There are some injuries that directly cause damage to the nerves. Sometimes, surgeons can damage a nerve during surgery, which eventually leads to peripheral neuropathy.
Vascular disorders – These conditions limit or reduce blood flow to specific parts of the body. As a result, they can cause damage to certain nerves.
Idiopathic neuropathy – Commonly, healthcare professionals cannot determine the exact cause of this disorder. In such cases, it is called idiopathic peripheral neuropathy.

How to Prevent Peripheral Neuropathy?

While not all the risk factors and causes of this disease are preventable, there are some tips that may help reduce the risk. These include:

Adopting a balanced diet – It is important to get enough vitamins, especially vitamin B12 and B6.
Physical exercises – Generally, it is recommended to aim for at least 30 minutes of physical exercise per day. It helps get and maintain a healthy weight and delay the onset of type 2 diabetes.
Safety equipment – Physicians recommend wearing protective equipment during work or contact sports because injuries are a common cause of nerve damage.
Treatment for chronic health conditions – These include hypertension (high blood pressure), type 2 diabetes, and others.
Limit or avoid alcoholic drinks
Avoid prolonged exposure to toxins, poisons, and heavy metals

Diagnosis

In most cases, peripheral neuropathy is diagnosed by using a combination of methods. These include:

Physicians often ask some questions about the symptoms and medical history to get more clues about the disease if they suspect peripheral neuropathy. They may also ask about other diseases and factors, including type 2 diabetes, lifestyle and habits, and others.
Neurological and physical examinations – During these procedures, doctors will check for abnormalities linked to the disease, such as changes in the ability to feel sensations, muscle weakness, problems with balance and coordination, and others.
Tests – However, to confirm this disorder, doctors should perform some tests, including electromyogram, nerve ultrasound or biopsy, genetic tests, MRI (magnetic resonance imaging), blood tests, and others.

Treatment

Healthcare professionals often prescribe different treatments for people with peripheral neuropathy because they depend on several factors. For example, the severity and exact location of the affected nerve, existing health problems, age, and preferences. Generally, physicians often recommend the following treatments:

Medicines – These include injections, pills that are taken orally, patches, and slow-release medicines.
Surgery – During this procedure, surgeons will reconnect the cut nerves and ease pain.
Physical therapy – This treatment involves specific exercises that help improve pain symptoms and recover from injuries.
Devices and wearable equipment – In more severe cases, doctors often recommend braces, canes, and walkers, and prescribe footwear.
Podiatry and foot care – Most people with peripheral neuropathy experience problems with the feet. For example, sores and infections, soft tissue and bone changes, and others.
Pain treatments – When pain caused by this disorder does not improve with medicines, doctors may recommend acupuncture, transcutaneous electrical nerve stimulation, injections, or surgery.

Frequently Asked Questions

Who does peripheral neuropathy affect?

While this condition can negatively affect anyone, some people are more likely to develop it. These include people with certain diseases (such as type 2 diabetes and others), a family history of peripheral neuropathy, and others. Moreover, the risk of peripheral neuropathy also increases with aging.

How quickly does peripheral neuropathy develop?

This disorder develops individually depending on the underlying cause. For instance, injuries cause the disease to develop instantly within several minutes or hours, but there are some disorders that may cause peripheral neuropathy to occur after months or even years.

Is peripheral neuropathy contagious?

This health condition is not contagious, but some infections (such as Hansen disease) that cause it can spread to other people. If you have additional questions, ask your healthcare provider.