Delirium is an acute change in mental state in which attention and awareness falter. It develops over hours to days, fluctuates through the day, and is usually worse at night. It always reflects something else: a medical illness, a drug effect, intoxication or withdrawal, or several causes acting together.
Three questions organise the topic: how to recognise delirium, why it happens, and what to do about it. Recognition comes first because every decision in delirium starts from it.
Choose a route through the topic
A reader new to delirium can begin with how it looks and work forward; a reader with a specific question can go straight to the note that answers it.
- Delirium Clinical Picture shows what delirium looks like and how its quiet and agitated forms differ from dementia.
- Delirium Pathophysiology follows the proposed mechanisms that link many different triggers to one shared attentional failure.
- Delirium Diagnosis covers bedside recognition and the predisposing and precipitating factors worth searching for.
- Delirium Diagnostic Workup traces the cause-finding sequence once delirium is recognised, from bedside checks to selective testing.
- Delirium Management follows the cause-first hierarchy, supportive measures, and the narrow place of drugs.
- Delirium Prognosis explains how often delirium persists and why resolution before discharge shapes what follows.
The useful sequence is the clinical picture first, then mechanisms, then recognition and workup, then management and outlook, because every decision in delirium starts from recognising it and finding its cause.