Alerts and Notices
SynopsisDelirium (also known as encephalopathy) is an acute confusional state that presents as fluctuations in level of alertness, inattention, or altered level of consciousness and disorganized thinking. Delirium develops subacutely over hours to days and can persist for days to weeks. Patients with underlying cognitive deficits, older individuals, and those with functional disabilities are at higher risk for developing delirium given decreased cognitive reserve.
Etiologies of delirium are broad and include systemic toxic, metabolic, nutritional, infectious, or pharmacologic causes as well as acute brain disorders (eg, stroke, seizures). Delirium is classically thought to be transient, although not all patients return to their baseline. Delirium can be hyperactive, with psychomotor agitation and emotional disturbances, or hypoactive.
See Drug Reaction Data table for a list of potential pharmacologic causes. Related topic: Drug-induced psychosis.
R41.0 – Disorientation, unspecified
2776000 – Delirium
Differential Diagnosis & Pitfalls
- Nonconvulsive status epilepticus
- Psychotic disorders
- Wernicke encephalopathy
- Transient global amnesia
- Bifrontal lesions
- Acute disseminated encephalomyelitis
- Infectious or inflammatory encephalitis
Drug Reaction DataBelow is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.