Delirium
An acute, fluctuating disturbance of attention and awareness caused by an underlying illness, substance effect or withdrawal: treat it as a medical syndrome until the cause is found.
Definition
Delirium is an acute, fluctuating disturbance of attention, awareness or cognition caused by an underlying physical illness, medication or substance effect, or withdrawal. It may be hyperactive, hypoactive or mixed.
First principles
Acute change and inattention are the diagnostic anchors
Delirium develops over hours or days and fluctuates. Look for a new change in concentration, responses, perception, mobility, appetite, sleep or social behaviour, using collateral history because the patient may not recognise the change. Inattention and altered alertness are more useful anchors than the label of confusion alone.
This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.

