Nerves could be described as the body's telephone lines. They carry messages from the brain to the various muscles, glands and organs, and then relay messages back to the brain from those same sources. Nerve damage will often affect the organ that the nerve supplies, by destroying the brain's ability to communicate with it. Other nerve damage symptoms can result from an inability to send sensory input back to the brain.
Pain and Other Sensory Disturbances
Pain can be a symptom of a wide variety of physical ailments, and nerve damage is no exception. In certain cases, the pattern of pain can give some indication of which specific nerves are involved in an injury. For example, injury of the radial nerve can cause symptoms in the back of the hand and in the fingers that are closest to the thumb, according to MedlinePlus.
Numbness and tingling are also sometimes associated with nerve damage. Paresthesia, the familiar sensation commonly described as "pins and needles" can be a symptom of nerve damage.
Muscle Weakness
Nerves carry impulses from the brain that tell skeletal muscles to move. Skeletal muscles are those that can be controlled voluntarily and are used in locomotor skills. When the nerve supply to a skeletal muscle is impaired, the individual's ability to use that muscle may suffer as well.
For example, MedlinePlus notes that damage to the femoral nerve can result in weakness of the muscles to the leg, resulting in difficulty when descending stairs. Damage to cranial nerve III, the oculomotor nerve, can impair the muscles that lift the eyelid. This can cause the eyelid to droop, a condition known as ptosis.
Autonomic Dysfunction
Damage to nerves that regulate involuntary body functions can cause symptoms that affect such things as blood pressure, digestion and vision. These functions are controlled by the autonomic nervous system.
Smooth muscles are those that contract to perform involuntary actions such as moving food through the digestive system. The autonomic nervous system supplies impulses that tell the smooth muscles to contract. The New York Times Health Guide lists numerous gastrointestinal effects that can result from autonomic nerve damage, including nausea, vomiting, diarrhea, impotence and bloating of the abdomen.
The cardiovascular system can be severely impacted by autonomic nerve damage as well. Symptoms of autonomic nerve damage to the cardiovascular system include irregular heartbeat, abnormally, high or low blood pressure, and abnormally rapid or slow heart rate.
