Peripheral neuropathy is the weakening, inflammation or damage of the peripheral nerves. When the peripheral nerves are weakened, the way we feel things changes; there may be numbness or pain. Symptoms vary greatly depending on the location and type of nerve damage. For example, in some cases there may be a complete loss of sensation in that part of the body, while in others there may be muscle weakness. In some cases, there may be changes in the functioning of internal organs, such as changes in bladder function, bowel movement and so on.
A peripheral nerve is any nerve outside the brain. In medicine, the brain is called the central nervous system, and all the nerves that leave the brain are called peripheral nerves. These peripheral nerves are responsible for all sensation, control of movement and control of internal organs through what is called the autonomic nervous system.
The most common symptoms of peripheral neuropathy are changes in sensation in the upper and lower limbs, also known as glove and sock syndrome. It is a condition in which a person often feels pins and needles in the feet, numbness in the feet that slowly spreads up the legs. As the peripheral neuropathy progresses, many people would also experience changes in sensation in their hands.
In some cases, there is more pain than numbness. A small number of people may also experience muscle weakness and paralysis.
In some people, the autonomic nervous system can also be affected. They may experience changes in bowel movements, inconsistent urination, difficulty tolerating heat, changes in blood pressure, dizziness or lightheadedness, and so on.
What are the most common causes of peripheral neuropathy?
Peripheral neuropathy can be caused by many conditions, some of the most common causes of neuropathy are:
- Diabetes is perhaps the most common cause of peripheral neuropathy. It is thought that more than half of those living with diabetes have neuropathy, although not all may recognise it due to the mildness of the symptoms. However, in a third of people living with diabetes, peripheral neuropathy is quite severe. Peripheral neuropathy in diabetes is caused by a combination of factors, including direct damage from high glucose levels, disruption of the blood supply due to damage to the capillaries, and so on. Peripheral neuropathy in diabetes can be painful or cause numbness in the limbs. It increases the risk of trauma, infection and non-healing wounds in diabetes.
- Chemotherapy – Drugs used to treat cancer and related conditions are highly toxic to the nerves and often cause peripheral neuropathy.
- Alcoholism – prolonged alcohol abuse leads to poor diet and vitamin deficiencies, which in the long run can cause peripheral neuropathy.
- Autoimmune diseases – this is a group of more than 100 diseases and unfortunately many of them are on the increase, either due to diet or environmental changes. Some of these diseases are more likely to cause peripheral neuropathy than others. For example, peripheral neuropathy can occur in lupus, celiac disease, Sjögren’s syndrome, rheumatoid arthritis, necrotizing vasculitis and chronic inflammatory demyelinating polyneuropathy.
- Exposure to toxins – Many toxins are nerve damaging, such as organophosphates used as insecticides. So accidental exposure to them can lead to nerve damage.
- Infections – Certain viral and bacterial infections are known to cause nerve damage. These include HIV, diphtheria, hepatitis C, shingles, Epstein-Barr virus, Lyme disease and many others.
- Trauma or pressure on the nerve – Trauma, accidents, sports injuries often lead to damage to peripheral nerves. Similarly, sprains and strains, changes in bones such as spinal vertebrae can cause undue pressure or trapping of nerves leading to peripheral neuropathy.
- Vitamin deficiency – although rarely the cause of peripheral neuropathy in developed countries, it cannot be ruled out. In the developed world, vitamin deficiencies are not due to diet, but rather to chronic conditions such as bowel disease or some hormonal disorders.
- Other diseases – apart from the conditions mentioned above, any disease condition can alter sensation in the peripheral nerves, such as thyroid disease, kidney disease and so on.
Peripheral neuropathy is not just discomfort or pain; it increases the risk of skin trauma due to the lack of sensation. A person living with peripheral neuropathy is more likely to get an infection. Peripheral neuropathy also increases the risk of falls and much more.
This is why it is important to detect peripheral neuropathy as early as possible. Early detection also means a higher chance of disease reversal. The most effective way to prevent the progression of peripheral neuropathy is to treat the underlying cause. Other preventive measures include regular exercise, physiotherapy and dietary changes. Foods rich in vitamin B12 and omega fatty acids are known to help prevent the progression of peripheral neuropathy.
In peripheral neuropathy, natural methods are more effective than chemical drugs, which mostly help to relieve the symptoms.