Neuralgia is one of the common symptoms in neurology. This type of pain refers to the pain felt without external stimulation, also known as spontaneous pain. There are many types of spontaneous pain, which can be divided into peripheral neuralgia and central neuralgia according to the location of the lesion. Those with unknown causes are called primary neuralgia, and those with clear causes are called secondary (or symptomatic) neuralgia. The lesion site may be the nerve root, nerve plexus or nerve trunk. It is often named after the peripheral nerve involved in the lesion. Local pain caused by other local lesions stimulating peripheral receptors and somatic pain caused by lesions in the sensory conduction pathways of the central nervous system generally do not fall into the category of neuralgia.