Neuropathic pain is initiated or caused by a primary lesion or dysfunction of the nervous system. A consensus regarding the classification and assessment of neuropathic pain has yet to be reached. The diseases responsible for neuropathic pain are diverse; the clinical presentation of pain can vary widely between individuals despite the same underlying aetiology. Common features of neuropathic pain include spontaneous and evoked pains. Investigations may help to identify evidence of nerve dysfunction but it cannot be assumed that it is necessarily the cause of their pain.