For families and carers

“New confusion” has a name: delirium

Delirium is a sudden change in a person’s thinking, memory or alertness, usually caused by an illness, an injury, surgery or medicines. It affects 1 in 4 older people in hospital. Many families have never heard its name.

For staff Resources to print and share Ward poster with a QR code for families, plus leaflets and editable Word files. See the resources

This website focuses mainly on delirium in older people outside intensive care. Much of it is relevant in an ICU, but Vanderbilt has more specific ICU information. It does not cover paediatric delirium; the Resources page links to specialist information for babies, children and young people.

Written by Professor Alasdair MacLullich, Professor of Geriatric Medicine at the University of Edinburgh. Page last reviewed: July 2026.

Free course for families

Understanding delirium, at your own pace

Eight short sections explain delirium, its treatment and recovery, and how families and friends can help. They include short films, questions with explanations, and a summary to keep.

About 30 minutes. No sign-up needed.

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Is this delirium? The common signs

Delirium appears over hours or days. The person is different from their normal self. You might notice:

Sudden confusion

Losing track of where they are, or what day or time it is. Clearly more muddled than normal.

Trouble paying attention

They find it hard to follow a conversation. They may stop responding in the middle of a sentence or seem not to hear you.

Unusual drowsiness

Much sleepier than usual, sleeping through visits, or slow to respond. If they are hard to wake or barely responding, get emergency help now.

Restlessness or agitation

Pacing, fiddling, pulling at drips, sometimes fear or anger.

New suspicion, or seeing things

Believing others mean harm, or seeing people or animals that are not there.

Symptoms that come and go

Clearer in the morning, but confused by teatime. Evenings and nights are often worse.

New sudden confusion can be caused by serious illness and needs medical assessment now. Outside a care setting, phone the local emergency number now. In a hospital or care home, tell staff immediately and describe the change from normal. If the person is hard to wake, struggling to breathe, has signs of a stroke, has a seizure or head injury, or is getting worse quickly, call the local emergency number immediately. Do not wait to see if it settles. What to do now.

Delirium is not dementia

Dementia usually develops slowly, over months and years. Delirium starts over hours or days, and it usually improves once its causes are found and treated. The two conditions are often mistaken for each other, including by professionals.

If someone who already has dementia suddenly gets much worse, treat the change as possible delirium.

See the differences at a glance

Dementia changes over months to years years Delirium changes over hours to days days

Someone to talk to

A sudden illness can leave families worried and unsure where to turn. Ask the team looking after the person about local services for families, carers and patients. Our resources page also links to specialist information and a list of dementia organisations by country.

Find information and support

Printable help to keep or share

Clear guides for the ward, the kitchen drawer, or a relative who does not use the internet. Choose A4 or US Letter, or download the combined family pack.

What is delirium?

The meaning, common signs, causes, treatment and what to do.

Download What is delirium? (PDF)

Delirium action guide

The signs, who to contact, and when to seek emergency help.

Download the Delirium action guide (PDF)

Helping at the bedside

Simple things that may reduce fear and confusion during the day.

Download Helping at the bedside (PDF)

See all seven downloads

Questions families ask

Straight answers to the questions that come up most, including how long delirium lasts, confusion after an operation and whether delirium is a sign of dying. See all questions.

Comics to help explain delirium

Illustrated stories for people with delirium, families and carers. Choose a topic and read a comic, with a text transcript.

Browse the delirium comics