This is a condition in which inflammation or degeneration of one or more nerves takes place. It may be localised or widespread and is commonly known as polyneuritis, multiple neuritis or peripheral neuritis. Symptoms depend on whether the nerve involved is a motor (carrying electrical impulses from the central nervous system to a muscle to make it contract) or sensory (carrying sensations to the central nervous system) nerve. If a sensory nerve is involved, the main symptom is pain, as in neuralgia. If a motor nerve is involved, the main symptom is a degree of paralysis of the muscle that is supplied by that nerve. The overlying skin may become shiny or ulcerated, the nails ridged or pitted and osteoporosis may develop. Treatment primarily involves identifying the cause and removing the toxin affecting the nerves.