Peripheral neuropathy is a condition resulting from damage to your peripheral nerves. These nerves are crucial as they form the communication network between your brain and spinal cord (the central nervous system) and the rest of your body. When these nerves are damaged, it can disrupt this communication, leading to a variety of symptoms. Typically, peripheral neuropathy causes weakness, numbness, and pain, often in the hands and feet. However, it’s important to understand that it can affect other parts of your body and impact various bodily functions, including digestion and urination.
To fully grasp peripheral neuropathy, it’s helpful to understand the role of the peripheral nervous system. This system uses motor nerves to transmit signals from the brain and spinal cord to your muscles, controlling movement. It also uses sensory nerves to relay information from your skin and other parts of your body back to the central nervous system, allowing you to experience sensations like touch, temperature, and pain.
Alt text: Diagram illustrating the network of peripheral nerves extending from the spinal cord throughout the body.
Peripheral neuropathy can arise from a wide array of factors, including traumatic injuries, infections, metabolic disorders, inherited conditions, and exposure to toxins. Notably, diabetes is one of the most prevalent causes of this condition. Individuals suffering from peripheral neuropathy often describe their pain as stabbing, burning, or tingling. In many cases, particularly when the underlying cause is treatable, symptoms can improve. Furthermore, various medications are available to effectively manage and reduce the pain associated with peripheral neuropathy.
Understanding Peripheral Neuropathy: How it Affects Your Body
The peripheral nervous system is an intricate network of nerves branching out from your brain and spinal cord. Each of these nerves has a specific function, and the symptoms of peripheral neuropathy depend largely on which types of nerves are affected. These nerves are broadly categorized into:
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Sensory nerves: These nerves are responsible for transmitting sensations from your skin and body to the spinal cord and brain. This includes sensations like temperature, pain, vibration, and touch. Damage to sensory nerves can lead to changes in how you perceive these sensations.
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Motor nerves: Motor nerves control the movement of your muscles. They transmit signals from the brain and spinal cord to your muscles, initiating and coordinating voluntary movements. Damage to motor nerves can result in muscle weakness and impaired movement.
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Autonomic nerves: This group of nerves regulates involuntary bodily functions. These functions are essential for life and occur without conscious effort. Autonomic nerves control blood pressure, heart rate, sweating, digestion, bladder function, and more. Damage to these nerves can disrupt these vital automatic processes.
Symptoms of Peripheral Neuropathy: Recognizing the Signs
The symptoms of peripheral neuropathy are diverse, reflecting the wide range of functions controlled by the peripheral nerves. Recognizing these symptoms early is crucial for timely diagnosis and management. Common symptoms include:
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Gradual onset of numbness, tingling, or prickling: This often begins in the feet or hands and may slowly spread up into your legs and arms. This sensation is frequently described as “pins and needles.”
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Sharp, jabbing, throbbing, or burning pain: Neuropathic pain can take many forms and is often described as intense and unpleasant. It can be spontaneous or triggered by certain stimuli.
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Extreme sensitivity to touch: Even light touch, such as from bedsheets or clothing, can be intensely painful. This is known as allodynia.
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Pain during activities that shouldn’t cause pain: This can include pain in your feet when simply putting weight on them or even when they are just under a blanket.
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Lack of coordination and falling: Muscle weakness and sensory loss can lead to difficulties with balance and coordination, increasing the risk of falls.
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Muscle weakness: This can make it difficult to perform everyday tasks, such as lifting objects or walking.
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Feeling as if you’re wearing gloves or socks when you’re not: This phantom sensation is a common and peculiar symptom of peripheral neuropathy.
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Inability to move if motor nerves are affected: In severe cases, damage to motor nerves can lead to paralysis.
When autonomic nerves are affected, symptoms can include:
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Heat intolerance: Difficulty tolerating high temperatures and excessive sweating or, conversely, the inability to sweat.
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Excessive sweating or not being able to sweat: Disruption of sweat gland control can lead to either excessive or insufficient sweating, impacting body temperature regulation.
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Bowel, bladder, or digestive problems: Autonomic neuropathy can affect the muscles and nerves controlling digestion and elimination, leading to constipation, diarrhea, incontinence, or difficulty emptying the bladder.
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Drops in blood pressure: This can cause dizziness or lightheadedness, especially when standing up quickly (orthostatic hypotension).
Peripheral neuropathy can affect a single nerve (mononeuropathy), two or more nerves in separate areas (multiple mononeuropathy), or many nerves throughout the body (polyneuropathy). Carpal tunnel syndrome, a condition affecting a nerve in the wrist, is a common example of mononeuropathy. However, polyneuropathy, affecting multiple nerves, is the most common form of peripheral neuropathy.
Alt text: Photograph depicting a person holding their foot in pain, highlighting foot pain as a symptom of peripheral neuropathy.
What Causes Peripheral Neuropathy? Common and Less Common Causes
Peripheral neuropathy is not a disease itself but rather a result of nerve damage caused by various underlying conditions. Understanding these causes is vital for effective treatment and prevention. Some of the health conditions that can lead to peripheral neuropathy include:
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Diabetes and metabolic syndrome: This is the most common cause of peripheral neuropathy, particularly diabetic neuropathy. High blood sugar levels over time can damage nerves. More than half of people with diabetes will develop some form of neuropathy.
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Autoimmune diseases: In these conditions, the body’s immune system mistakenly attacks its own tissues, including nerves. Examples include:
- Sjogren’s syndrome
- Lupus
- Rheumatoid arthritis
- Guillain-Barre syndrome
- Chronic inflammatory demyelinating polyneuropathy (CIDP)
- Vasculitis
Certain cancers related to the immune system can also trigger polyneuropathy as a paraneoplastic syndrome, an autoimmune response to cancer.
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Infections: Certain viral and bacterial infections can directly or indirectly damage nerves. These include:
- Lyme disease
- Shingles (herpes zoster)
- Hepatitis B and C
- Leprosy
- Diphtheria
- HIV
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Inherited disorders: Some forms of neuropathy are hereditary, meaning they are passed down through families. Charcot-Marie-Tooth disease is a well-known example of an inherited neuropathy.
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Tumors: Both cancerous (malignant) and noncancerous (benign) tumors can cause neuropathy. They can grow directly on nerves or press on surrounding nerves, leading to damage.
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Bone marrow disorders: Certain bone marrow disorders can lead to abnormal protein production in the blood, which can damage nerves. These include:
- Monoclonal gammopathies (abnormal proteins in the blood)
- Multiple myeloma (a type of bone marrow cancer)
- Lymphoma (cancer of the lymphatic system)
- Amyloidosis (a rare disease where abnormal proteins accumulate in organs and tissues)
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Other diseases: Various other health conditions can contribute to neuropathy, including:
- Kidney disease
- Liver disease
- Hypothyroidism (underactive thyroid)
Other factors that can cause neuropathies include:
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Alcohol use disorder: Chronic alcohol abuse and the associated poor dietary habits can lead to vitamin deficiencies and nerve damage.
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Exposure to poisons: Toxic substances, including industrial chemicals and heavy metals like lead and mercury, are neurotoxins and can cause peripheral neuropathy.
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Medicines: Certain medications, particularly chemotherapy drugs used in cancer treatment, are known to cause peripheral neuropathy as a side effect.
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Injury or pressure on the nerve: Physical trauma from accidents, falls, or sports injuries can directly damage or sever peripheral nerves. Nerve compression or pressure can also occur from casts, crutches, or repetitive motions like typing. Carpal tunnel syndrome is a common example of pressure-induced neuropathy.
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Low vitamin levels: Deficiencies in certain vitamins, particularly B vitamins (B1, B6, B12), vitamin E, and copper, are essential for nerve health and can lead to neuropathy.
In some instances, despite thorough investigation, the cause of peripheral neuropathy cannot be identified. This is termed idiopathic peripheral neuropathy.
Risk Factors for Peripheral Neuropathy: Who is at Risk?
Several factors can increase your risk of developing peripheral neuropathy. Being aware of these risk factors allows for proactive measures to be taken to mitigate the risk where possible. Key risk factors include:
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Diabetes: Poorly controlled blood sugar levels significantly elevate the risk of diabetic neuropathy.
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Alcohol misuse: Chronic and excessive alcohol consumption increases the risk of nerve damage.
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Vitamin deficiencies: Low levels of specific vitamins, especially vitamin B12, are linked to increased neuropathy risk.
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Infections: Certain infections like Lyme disease, shingles, hepatitis B and C, and HIV are known risk factors.
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Autoimmune diseases: Conditions such as rheumatoid arthritis and lupus, where the immune system attacks the body’s own tissues, increase neuropathy risk.
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Kidney, liver, or thyroid disorders: These conditions can disrupt normal bodily functions and increase the likelihood of nerve damage.
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Exposure to toxins: Occupational or environmental exposure to toxic substances elevates the risk.
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Repetitive motion: Jobs or activities involving repetitive movements can lead to nerve compression and neuropathy, such as carpal tunnel syndrome.
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Family history of neuropathy: Having a family history of neuropathy, particularly inherited forms, increases your genetic predisposition.
Complications of Peripheral Neuropathy: Potential Long-Term Effects
Peripheral neuropathy, if left unmanaged, can lead to various complications that significantly impact quality of life. These complications arise primarily from the loss of sensation and muscle weakness associated with nerve damage:
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Burns, skin injuries, and wounds on the feet: Numbness can prevent you from feeling temperature changes or pain, making you unaware of injuries, burns, or developing wounds, especially on the feet.
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Infection: Due to reduced sensation, injuries, particularly to the feet, may go unnoticed and untreated, increasing the risk of infections. In people with diabetes, foot infections can be particularly serious and slow to heal. Regular foot checks and proper foot care are essential.
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Falls: Muscle weakness, loss of balance, and impaired sensation contribute to an increased risk of falls. This is particularly concerning for older adults and can lead to fractures and other injuries.
Prevention of Peripheral Neuropathy: Steps You Can Take
While not all causes of peripheral neuropathy are preventable, particularly inherited conditions, there are significant steps you can take to reduce your risk and manage the condition effectively. Prevention strategies focus on managing underlying medical conditions and adopting healthy lifestyle choices.
Manage Underlying Conditions
The most effective way to prevent peripheral neuropathy is to diligently manage underlying medical conditions that increase your risk. This is particularly crucial for diabetes.
- Diabetes management: Strictly controlling blood sugar levels through diet, exercise, and medication, as prescribed by your healthcare provider, is paramount in preventing or slowing the progression of diabetic neuropathy.
Make Healthy Lifestyle Choices
Adopting and maintaining healthy lifestyle habits significantly supports nerve health and reduces neuropathy risk:
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Eat a balanced diet: Consume a diet rich in fruits, vegetables, whole grains, and lean protein to nourish your nerves. Ensure adequate intake of vitamin B12 by including meat, fish, eggs, low-fat dairy, and fortified cereals in your diet. If you are vegetarian or vegan, discuss B12 supplementation with your healthcare provider.
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Exercise regularly: With your doctor’s approval, aim for at least 30 minutes to an hour of moderate-intensity exercise most days of the week. Regular physical activity improves overall health and nerve function.
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Avoid factors that may cause nerve damage:
- Limit or avoid alcohol: Excessive alcohol consumption is a significant risk factor for neuropathy.
- Quit smoking: Smoking damages blood vessels and can worsen neuropathy.
- Avoid exposure to toxins: Minimize exposure to industrial chemicals, heavy metals, and pesticides.
- Practice good ergonomics: Avoid repetitive motions and maintain proper posture to prevent nerve compression, especially in the workplace.
When to Seek Medical Advice for Peripheral Neuropathy
It is crucial to seek medical attention promptly if you experience unusual tingling, weakness, pain, or numbness in your hands or feet. Early diagnosis and treatment are essential for managing symptoms, preventing further nerve damage, and addressing the underlying cause of the neuropathy. Do not delay seeking medical help if you notice these symptoms. Early intervention provides the best opportunity to control your symptoms and improve your long-term outcome.
Peripheral neuropathy care at Mayo Clinic
Sept. 02, 2023
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