What is delirium?

Delirium is when you have a sudden change in the way you think or behave. It is often a symptom of a serious illness.

Delirium can develop quickly and lasts for a few days. It is common in older people, but it can happen at any age.

If you have delirium when in hospital, you may be at higher risk of medical complications.

What are the symptoms of delirium?

Delirium can cause a range of symptoms, including sudden confusion and changes in behaviour. You may notice that someone with delirium:

• is confused or forgetful
• doesn't know the time or where they are
• acts differently from usual
• is unsettled, sleepy or has changes in their sleep pattern
• feels scared, upset, irritable, angry or sad
• sees things that are not there (hallucinations)
• loses control of bladder or bowels (incontinence)

These symptoms can start suddenly, over a few hours or days. They can last for a few days or weeks.

Delirium, dementia and depression

Delirium, dementia and depression can seem similar, but they are different.

• Dementia is a condition where a person's memory, thinking, understanding or judgement gets worse slowly over time.
• Depression means having a low mood for at least 2 weeks.
• Delirium occurs suddenly. Symptom of delirium can change throughout the day.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

When should I call an ambulance or go to the emergency department?

Delirium is a medical emergency. If you have delirium, you are at a high risk of harming yourself or someone else. The cause of your delirium needs to be identified and treated.

If you notice a sudden change in someone's mental or physical condition, it is important to tell a doctor.

What should I do while waiting for an ambulance?

While waiting for an ambulance, keep the person safe and try to keep them calm. Provide paramedics with important details about their:

• medical history
• medicines
• recent changes in behaviour

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

What causes delirium?

Delirium is often caused by changes in your health, such as a physical illness or infection. It can also result from a change in your prescription medicines.

Other causes for delirium include:

• difficulty going to the toilet (constipation or not being able to empty your bladder)
• dehydration or not eating enough food
• severe pain
• some over-the-counter medicines
• drinking a lot of alcohol
• withdrawal from alcohol, cigarettes or medicines — especially sleeping pills
• changes in your environment, such as being in hospital

It is not always possible to find the cause of delirium.

Who is at risk of delirium?

You are at a higher risk of delirium if you:

• are aged over 65 years, or aged over 45 years for Aboriginal and/or Torres Strait Islander people
• take multiple medicines or have had recent changes to medicines
• have had recent surgery — such as hip or heart surgery
• are living with depression
• are sick or frail
• have poor eyesight or hearing loss
• have a cognitive impairment — such as dementia, intellectual disability or brain injury
• have had delirium before

How is delirium diagnosed?

Your doctor can diagnose delirium by asking you or people with you about any sudden changes in your behaviour or thinking. Your doctor may check you a few times throughout the day before making a diagnosis.

To find the cause, your doctor may:

• do a physical examination
• order tests, such as blood tests, urine tests and x-rays
• review your prescription medicines and any possible recent changes to your prescriptions
• check if you are in pain

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

How is delirium treated?

Treatment for delirium focuses on finding and addressing the cause and providing supportive care.

Your doctor may treat delirium by:

• changing your prescription medicines
• giving you intravenous fluids
• prescribing antibiotics if you have an infection
• prescribing antipsychotic medicines when other methods to manage delirium don't work

Supportive care

It can be reassuring for someone with delirium to see familiar faces. You may be encouraged to stay with your loved one if they are in hospital and have delirium.

Here are some tips to help and care for someone with delirium:

• Speak slowly and clearly.
• Identify yourself and the person by name.
• Avoid arguing with them and remind them of the time and date and where they are.
• Help them put on their hearing aids and glasses.
• Let them walk if they want, ensuring they are safe from falling and hazards.
• Bring them familiar items, such as photos, clothes or favourite music.
• Share personal information with staff that may help calm and orient the person. This can be names of family and friends, hobbies and significant events.

What are the complications of delirium?

Delirium can lead to several complications, including:

• falling and injuring yourself
• pressure sores from being immobile
• dehydration and malnutrition due to difficulty eating and drinking

Can delirium be prevented?

Delirium can be prevented with proper care. If you are at risk, your doctor may:

• check your medicines and adjust those that may increase your risk
• encourage you to eat and drink to stay hydrated and nourished
• help you stay active
• If you are in hospital, your healthcare team can try to prevent delirium by:
• developing a delirium prevention plan with you and your family or carer
• communicating clearly
• encouraging you to eat and drink to stay hydrated and nourished
• managing your pain effectively
• regularly reminding you of the place, time and date
• helping you wear your glasses and hearing aids
• helping you get out of bed for meals or after a procedure

Resources and support

• NSW Government provides a brochure about delirium.
• Carers Australia offers services and support for carers across Australia.
• Department of Health Victoria explains the differences between dementia, depression and delirium.
• You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

Do you prefer to read in languages other than English?

• Dementia Australia provides resources in multiple languages.
• NSW Government's Multicultural Health Service offers translated phrases to say to someone with delirium in multiple languages.

Looking for information for Aboriginal and/or Torres Strait Islander people?

• Dementia Australia offers resources about dementia for Aboriginal and/or Torres Strait Islander people.
• Australian Indigenous HealthInfoNet provides a factsheet on delirium for Aboriginal and/or Torres Strait Islander people.