What is delirium?

Delirium is where there is a recent change in a person’s thinking and behaviour that can come and go. The person often has difficulty paying attention. They may be very sleepy or restless, or be thinking in a disorganised way.

Delirium can be caused by changes in a person’s health, such as an infection or a medication change. It often occurs in older people in hospital. People with dementia are six times more likely to get delirium than other people. 

People with cognitive impairment, or hearing or vision loss, are also at increased risk of delirium. People who have delirium when they are in hospital are at higher risk of developing further medical complications. 

Causes of delirium

Delirium can be caused by any illness, as well as things such as constipation, dehydration and pain. Many people will have more than one problem leading to their delirium. Sometimes it is difficult to find the cause.

Diagnosis of delirium

A person with delirium may be confused and have problems with memory. They may be agitated or drowsy. To diagnose delirium, a health worker may talk to family, friends or carers about changes in the person’s behaviour or mental state. If there have been changes over a short period of time, the person might have delirium.

The health worker will also observe for changes in the person’s consciousness and thought patterns. If someone is found to have delirium, further tests may be done to find the cause.

Management of delirium

It is important to try and find the cause of delirium and treat that. Always report increasing confusion in a hospitalised person to a health care worker. It can also be helpful to do simple things like removing excess noise and making sure the person:

• sleeps well
• eats and drinks enough
• has familiar people around.

If a person is a risk to themselves or others, medication is sometimes used.