Definition: Delirium is defined by the acute onset of fluctuating cognitive impairment and a disturbance of consciousness. Cognition includes memory, language, orientation, judgement, conducting interpersonal relationships, performing actions (praxis), and problem solving. Delirium is thus marked by short-term confusion and changes in cognition. There is also rapid improvement in most cases when the causative factor is identified and eliminated. Abnormalities of mood, perception, and behavior are common psychiatric symptoms. Tremor, asterixis, nystagmus, incoordination, and urinary incontinence are common neurological symptoms. Common causes of delirium: 1) Central nervous system disorder Seizure (postictal, nonconvulsive status, status) Migraine Head trauma, brain tumor, subarachnoid hemorrhage, subdural, epidural hematoma, abscess, intracerebral hemorrhage, cerebellar hemorrhage, nonhemorrhagic stroke, transient ischemia 2) Metabolic disor