What is delirium?

Defining delirium

Delirium is a neuropsychiatric condition resulting in acute problems with attention, arousal and cognition for which there is normally an underlying cause.

It is a sudden confused state that happens when a person becomes physically unwell. Symptoms of delirium start quickly over hours or days. It can be frightening for the person and for family and carers. Delirium can be present for a number of weeks, but sometimes the person can take months to recover.

Confusion in delirium is used in a different way to how we use it in everyday conversation. In this context, confusion means not being fully aware of reality. This can include not being sure of the time of day, the place or things going on around us. The person can have strange ideas, almost like a dream, except they appear to be awake.

The word delirium takes its origin from Latin from the words ‘de’ which means ‘away’ and ‘lira’. which means ‘furrow, away from track’. 

Types of delirium

There are three different types of delirium:

• Hypoactive delirium. When the person is withdrawn.
• Hyperactive delirium. When the person is more agitated.
• Mixed delirium. When the person swings between the two extremes of hyper and hypoactive delirium.