Symptoms of Neuropathy
Because every nerve in the body has a specialized function, neuropathy causes a wide range of symptoms . People are affected differently, depending on the type of damaged nerve and where or to what degree the nerve is damaged.
What happens when peripheral nerves are damaged?
When the peripheral nervous system is damaged, the nerves are unable to communicate with your brain properly. For example, if your hand feels numb and swollen, you may look at your hand and it’s not swollen. Your nerves are sending the wrong signal to your brain, telling your brain that something is wrong.
|Nerve||Nerve Function||Effects of Damage|
|Motor||Sends signal from brain to muscle||Weakness, impaired motor skills and mobility|
|Sensory||Sends signal from sense organs to brain||Large fiber nerves: impaired position sense, balance, vibration
Small fiber nerves: Numbness, tingling, pain, impaired sense of temperature
|Autonomic||Involuntary body functions: heart rate, digestion, blood pressure, bladder function, etc.||Unstable “automatic” functions|
The most common symptoms include numbness, tingling, and prickling sensations, sensitivity to touch or muscle weakness. Other people have more extreme symptoms– burning pain (especially at night), muscle deterioration, paralysis, or organ/ gland dysfunction.
Three better-known neuropathies illustrate the differences in cause, type of nerves affected and symptoms:
Charcot-Marie-Tooth (CMT) is one of the hereditary motor and sensory neuropathies. Its symptoms include weakening and wasting of muscles in the lower legs and feet, gait abnormalities, loss of tendon reflexes, and numbness in the lower limbs. Currently incurable, this disease is the most commonly inherited neurological disorder, and affects approximately 1 in 2,500 people.
Guillain-Barré syndrome is a non-hereditary acute autoimmune disorder in which the body attacks the lining of the nerves. In acute neuropathies such as this, symptoms appear quickly and resolve slowly as damaged nerves heal. There may be periods with no symptoms followed by relapses. In other cases, symptoms stay the same for many months or years. Occasionally, the neuropathy is a symptom of another disorder like cancer.
Perhaps the best-known neuropathy, diabetic neuropathy (also referred to as diabetic nerve pain) occurs because of exposure of nerve fibers to high blood sugar. A combination of factors likely plays a role, including the complex interaction between nerves and blood vessels. High blood sugar interferes with the ability of the nerves to transmit signals. It also weakens the walls of the small blood vessels (capillaries) that supply the nerves with oxygen and nutrients. The type of nerve that is damaged determines its symptoms.