Department of Health

“We must recognise and respond to delirium as we would any other medical emergency…[if we don’t] the outcome is as bad for older patients as if they experienced an acute myocardial infarct” (Geriatrician, Clinical Leadership Group on Care of Older People in Hospital)

Delirium is a serious condition where the person experiences a disturbance in attention, perception, awareness and cognition. Delirium may be caused by general medical conditions (for example, infections, hypoxia), certain medications, intoxicating substances or a combination of these.

Delirium develops quickly and symptoms fluctuate throughout the day. It usually lasts for a few days but may persist for weeks or even months in vulnerable older adults1,2. Delirium may be the only sign of medical illness or a rapidly deteriorating patient.

Delirium can be hyperactive, hypoactive (‘quiet’ delirium) or mixed. Hyperactive delirium is characterised by increased motor activity, restlessness, agitation, aggression, wandering, hyper alertness, hallucinations and delusions, and inappropriate behaviour. Hypoactive delirium is characterised by reduced motor activity, lethargy, withdrawal, drowsiness and staring into space. It is the most common delirium in older people. ‘Mixed’ delirium is where people have features of hyperactive and hypoactive delirium.

Delirium symptoms develop quickly

Delirium develops quickly, over hours or days, and symptoms fluctuate throughout the day and are often worse at night.

Symptoms include:

  • difficulty directing, focusing, sustaining or shifting attention
  • confusion
  • fluctuating or reduced consciousness
  • disorientation to time and place (particularly time)
  • disturbance of the sleep-wake cycle, for example, agitated or restless at night and drowsy during the day
  • impaired recent memory
  • speech or language disturbances, for example, rambling speech
  • increased or decreased psychomotor activity
  • emotional disturbances, for example, fearfulness, irritability, anger, sadness
  • hallucinations and delusions
  • lethargy and fatigue.

1. Kiely, D., et al., Characteristics associated with delirium persistence among newly admitted post-acute facility patients. Journals of Gerontology Series A-Biological Sciences & Medical Sciences, 2004. 59(4): p. 344-9.

2. Dasgupta, M. and L.M. Hillier, Factors associated with prolonged delirium: a systematic review. International Psychogeriatrics, 2010. 22(3): p. 373-394.

Reviewed 05 October 2015


Was this page helpful?