Peripheral neuropathy is an umbrella term that denotes a disorder of, or damage to, the peripheral nervous system. The peripheral nervous system consists of all the motor and sensory nerves that connect the brain and spinal cord to the rest of the body (i.e., the nerves outside the central nervous system). The symptoms and physical findings associated with peripheral neuropathies vary greatly from case to case and may be extremely complex.
More than 100 different peripheral neuropathies are recognized, each with a distinguishing set of symptoms, development path, and prognosis. Disorders affecting only one nerve are described as a mononeuropathies while disorders affecting more than one nerve are called polyneuropathies. If two nerves affecting different parts of the body are involved, the disorder is described as a mononeuritis multiplex.
In some cases, symptoms emerge abruptly, progress rapidly, and are slow to subside. Some chronic forms emerge only gradually and progress slowly. Some chronic forms appear to be resolved but are subject to relapses. Most often, symptoms such as pain, tingling, and/or muscle weakness start in both of the feet (bilateral) and progress up the legs. This is usually followed by symptoms in the hands that progress up the arms.