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Australasian Delirium Association


What is delirium?

Delirium is a medical problem which can develop when people are acutely unwell and/or are undergoing medical treatment, such as surgery. Older people, especially those who have dementia, are more at risk of developing delirium at these times. Delirium is also common in people receiving palliative care, and children with fevers or after some anaesthetics. Although the cause is not always known, it is always a consequence of physical changes related to illness or its treatment (e.g. infection, pain, or the addition of medications).

Delirium causes changes to the person’s usual mental functioning. Its onset is rapid (hours or days). It is sometimes confused with other conditions (e.g. stroke, depression and dementia).

Delirium is a serious condition and, if not managed promptly, other complications can occur, such as falls, longer hospital stays and ongoing cognitive impairment. While delirium usually lasts for only a few days and can be reversed, delirium sometimes persists even after the underlying problems are treated.

In children, delirium due to fever usually happens at night, occurs during the early stages of their illness and is usually very brief. At present, little is known about how long delirium will last in children when it occurs due to other circumstances.

‘Acute confusion’ or ‘impaired cognition’ are other terms that might be used to refer to delirium.   (1-3)

How might the person’s behaviour change during delirium?

People who have delirium suddenly become confused, forgetful and less able to pay attention to others and their environment. They will have difficulty concentrating, and may be disoriented, easily distracted and unable to engage in conversation. They may also misinterpret situations, show unfamiliar swings in emotion and see, hear, think or believe things that are not real. What they say is often mixed up or makes only partial sense to others. For the person, it feels like being in a strange dream or nightmare. As the person with delirium has trouble understanding, communication will be more difficult than usual and the person may become frustrated or angry with you.

Behaviour can range from restlessness, irritability, combativeness and repetitive behaviours, to uncharacteristic quietness, sleepiness, or withdrawal. These behaviours often fluctuate during the day.

Though behaviour changes are similar in children, irritability, agitation, sleep wake disturbance and changing moods are more common. Like adults, children may experience hallucinations. (2-7)

How common is delirium?

Delirium is a common condition amongst older people in community, residential and acute care settings. Up to one third of older people have delirium when they are admitted to hospital, and from 33% to 92% of older people will develop delirium when they have surgery to repair their hip fracture. Though delirium occurs less often in older people living in the community, it is more common in people aged over 85 years. In residential aged care the rate of delirium can be high, often in association with pre-existing dementia. In Intensive Care Units about 2 out of every 3 patients will get delirium. Although delirium is common in older people and people receiving palliative care, anyone can become delirious when unwell.            

Although children are at risk of delirium, there little research about how common it is. At present,  studies suggest that about 10% of hospitalised children/adolescents and 17-66% of paediatric intensive care patients referred to inpatient psychiatry services suffer delirium.

People who have had delirium are more likely to experience it again. (3, 8-10)

Why do people get delirium?

Delirium is caused by an underlying acute medical/surgical/traumatic condition which requires treatment. Although we are still uncertain about why people get delirium, we do know that people are more at risk when personal factors create vulnerability (e.g. older age, illness and cognitive decline) and other factors or events occur to enhance this vulnerability (e.g. infections, dehydration, medication).

Factors which seem to make children more at risk of delirium include: young age, being male, pre-existing progressive cognitive impairment or intellectual disability, having pre-exisiting behaviour problems and carer anxiety or absence. Common factors that enhance vulnerability include sepsis, anaemia, hypoxia and trauma. Children are thought to be more vulnerable to delirium from fever and general anaesthesia than adults.     (3, 11-13)    

Is delirium the same as dementia or depression?

No. Delirium is also not a normal reaction to being unwell, being admitted to hospital or having surgery. It is not a normal change in mental function from ageing. It is important for the medical team treating the person to differentiate between a diagnosis of delirium, dementia and depression.

How is delirium treated?

Delirium is usually managed by firstly treating the cause. For example, if a urinary tract infection is causing delirium, antibiotics will be commenced; if dehydration is a cause, intravenous fluids may be given.

In addition, the following strategies may be used to help the person during their delirium:

  •   Keeping the hospital room as quiet and calm as possible, especially at night.
  •   Avoiding placing the person in a room near busy and noisy parts of the ward (e.g. nurses station)
  •    Avoiding moving the person from one room to another.
  •    Allocating someone to stay with the person.
  •    Gently reminding the person where they are, why they are in hospital and what day/time it is.
  •    Asking family and other familiar people to visit and sit with the person. For children, to be a constant presence who comforts the child.

If other calming strategies have not helped and the person is very distressed, sometimes medicines may be used for short periods of time to help calm the person.

What can you do to help?

    • Make sure your loved one is safe and arrange for a doctor to review their health status without delay. If you are worried, take them to the local hospital emergency department or arrange for an ambulance. The underlying cause of their delirium needs to be investigated and treatment commenced. Anyone with delirium is at high risk of harm and should be reviewed by a doctor as soon as possible.
    • Talk to health care staff about the person’s usual behaviour and mental function, along with what you know of their medical history, both recent and past. How recently the person’s behaviour has changed is an important part of the person’s health history, and you will be the person who is most aware of subtle changes and when they started.
    • Let healthcare staff know if the person has been diagnosed with dementia, depression or other conditions which affect their ability to think and respond.
    • Provide an up-to-date list of medications.
    • Always advise health care staff if you notice any further changes in the person’s mental or physical condition.
    • Assist with the person’s care if you choose to and feel safe.
    • If usually worn, encourage the person to wear their glasses and/or hearing aid.
    • Encourage or help them with eating and drinking throughout the day, while being aware of any diet and fluid restrictions.
    • During the course of the day gently remind the person about who you/the care staff are, what day and time it is (e.g. nearly lunch time) and where they are.
    • Open curtains and blinds for natural light, and so they can see where they are and what is happening.
    • If they talk about things or people you cannot see, provide reassurance about their safety. Respond to their emotions (e.g. fear). Don’t argue about facts.
    • Stay with them if your presence is calming or reassuring. You might find it distressing to be present, so enlist help and support from your other family, friends and health care staff.
    • Talk to the person in a calm, clear and simple way; perhaps about familiar family, friends, events and, with children, their favourite toys/stories/movies etc. Avoid complex questions and conversations.
    • Respond calmly to the person, even when they talk about things or events you cannot see or are unfamiliar with.
    • Limit visits/visitors if these increase the person’s delirium symptoms during or after the visit.
    • If the person becomes agitated try not to restrict their movements. It is important for a person with delirium to continue to move, walk and exercise, if possible.
    • Let healthcare staff know if you are feeling distressed and/or need more information about what is happening and what to do.

My family member is going home and is still not back to normal. What should I ask healthcare staff?

It can be helpful to discuss:

    • How confident and able you feel about caring/supporting the person after discharge, including what to do if the person refuses their medications, is aggressive, insists on leaving their home or becomes more confused.
    • Any concerns you have about how you will manage care responsibilities on discharge and how these might impact on you and the person going home.
    • Your own health, emotional concerns or other issues that may affect your ability to care or provide support while delirium symptoms are still present (e.g. poor health; work or other family commitments; grief reactions; stress or relationship issues)
    • The availability of support after the person is discharged, including a 24-hour contact number if you have any worries after discharge, a follow-up date when you will be contacted to see how you are managing and how your family member is progressing.

What do family members say about being with someone during delirium?

It can be helpful to know what other family members have said about their experiences during delirium. Family members in research studies say they feel unprepared for the sudden way delirium appears. They say that being with someone during delirium is confronting, shocking, scary and distressing.

Family members of older people often describe the person as lost or absent during delirium, including how sad and distressing this is for them. They also say delirium is a contradictory experience as the body of the person remains familiar whilst the person they know is no longer contactable. As some family members have said;

... he’s not with us, his mind is not with us. Physically he is. (10) 

… dad was a complete stranger. It was not dad anymore, it was a complete stranger. (10)

To family members, the way the person acts during delirium accentuates how different the person is and how lost the person they know has become. At the fore is the peculiar ways the person acts, often their loss of self-control and their presence in another world; behaviours that are unexpected, bizarre, and shocking; or in contrast, closed, quiet and distant. Hallucinations suggest the person inhabits an inaccessible other world which is perceived by the person as real. Family members say;

... It was as if she had her own video running in her head that we couldn’t see, but she was interacting with this mental image and you know, sometimes she’d be laughing and other times she’d be angry. And it’s hideous to watch. It’s really terrible. (10)

Being with the person and waiting for them to return to their prior self is a worrying time and is hard to bear.

… apart from a few, a few lucid moments he’s been troubled and confused and hallucinating the whole time. The whole time. (10) 

Whilst delirium is present family members describe having difficulty understanding what has, and is, happening. They can feel unsure about what to do to help, and feel helpless to control what the person says and how they act. They are concerned about future care needs and how these might be addressed. They can fear the person has developed dementia, brain damage, “gone mad”, or is close to death.  (4, 14-18)

What can I do to help myself?

Try not to become upset or be offended by what the person says or does whilst delirious. During delirium the person is not thinking clearly and is not themselves. They may not remember what they have said or done after delirium passes.
Talk to healthcare staff about how you are feeling and about any concerns you have, including about what you experience when with the person in delirium.
As healthcare staff for information about delirium and how to help.
Limit the amount of time you are with the person or the care you assist with if you become distressed. Healthcare staff can and will care for the person during delirium.

Be open with other family members about what is happening. Share information about delirium to help them to understand and support you.

Will the person remember what happened during their delirium?

After delirium passes, some older people are able to recall their experience. Some find remembering helpful, aiding their understanding about what happened, and providing a sense of relief. However, a range of disturbing emotions can also be felt when they remember their actions and words while delirious. Some express feelings of belittlement, guilt, shame, embarrassment, humiliation, or remorse. At times they explain their actions as being out of character, or ask for forgiveness. Encountering memories of delirium can mean confronting the reality of their experience, or viewing the episode as a dissociated event in their lives. Some older people want to forget the episode, or are hesitant to discuss their experience, seeming to play down their unusual experiences and discouraging discussion. Discussing their experiences can risk being viewed as foolish. At times denial, embarrassment or dismissal of their experience is revealed through incongruent laughter or minimisation of what occurred. These reactions suggest you may face unexpected rejection or dismissal when wanting to talk about delirium with the person. Although delirium has passed, older people who have experienced delirium may feel vulnerable and in need of continued family understanding and support.

Though family members are relieved when delirium subsides, some find their relationship has been irrevocably changed by the way the person acted. In addition, knowing more about what happened during their delirium than the person may be a burden. (5,14,19-25)  

Can I help prevent delirium from happening again?

Yes, you can help. It is important to focus on and minimise the risk factors for delirium for and with the person, including;

Preventing, identifying and seeking early treatment health problems, such as urinary tract infection, pain, dehydration and constipation.
Encouraging an adequate diet and fluid intake each day.
Encouraging the use of hearing aids and glasses.
Helping to manage pain, promoting sleep at night and mobility during the day.
Helping to manage any chronic health conditions.
Ensuring the person/you manage their medication regime with the help of their doctor, including pain management drugs.
Monitor for changes in behaviour after the person’s medication regime is changed (e.g. increased doses, adding new medications).
Monitoring for changes in mental function and seeking medical assessment early
Providing ongoing support, stability and love.


Information about delirium

    •  Intensive care – 
    •  The basics (of delirium) - 


1.            Cole M, Ciampi A, Belzile E, Zhong L. Persistent delirium in older hospital patients: A systematic review of frequency and prognosis. Age and Ageing. 2009;38(1):19-26.

2.            American Psychiatric Association. Neurocognitive disorders. In: American Psychiatric Association, editor. Diagnostic and statistical manual of mental disorders (DSM-5). Arlington, VA: Author; 2013. p. 591-602.

3.            Hatherill S, Flisher A. Delirium in children and adolescents: A systematic review of the literature. Journal of Psychosomatic Research. 2010;68:337-44.

4.            Stenwall E, Sandberg J, Jönhagen M, Fagerberg I. Relatives’ experiences of encountering the older person with acute confusional state: Experiencing unfamiliarity in a familiar person. International Journal of Nursing Practice. 2008;3(4):243-51.

5.            Stenwall E, Jönhagen M, Sandberg J, Fagerberg I. The older patient’s experience of encountering professional carers and close relatives during an acute confusional state: An interview study. International Journal of Nursing Studies. 2008;45(11):1577-85.

6.            Leentjens A, Schieveld J, Leonard M, Lousberg R, Verhey F, Meagher D. A comparison of the phenomenology of pediatric, adult and geriatric delirium. Journal of Psychosomatic Research. 2008;64:219-23.

7.            Turkel S, Trzepacz P, Tavare C. Comparing symptoms of delirium in adults and children. Psychosomatics. 2006;47(4):320-4.

8.            de Lange E, Verhaak P, van der Meer K. Prevalence, presentation and prognosis of delirium in older people in the population, at home and in long term care: A review. International Journal of Geriatric Psychiatry. 2013;28(2):127-34.

9.            Bruce A, Ritchie C, Blizard R, Lai R, Raven P. The incidence of delirium associated with orthopedic surgery: A meta-analytic review. International Psychogeriatrics. 2007;19(2):197-214.

10.          Siddiqi N, House A, Holmes J. Occurrence and outcome of delirium in medical in-patients: A systematic literature review. Age and Ageing. 2006;35(4):350-65.

11.          Laurila J, Laakkonen M, Laurila J, Timo S, Reijo T. Predisposing and precipitating factors for delirium in a frail geriatric population. Journal of Psychosomatic Research. 2008;65(3):249-54.

12.          Fong T, Tulebaev S, Inouye S. Delirium in elderly adults: Diagnosis, prevention and treatment. Nature Reviews Neurology. 2009;5(4):210-20.

13.          Grover S, Kate N, Malhotra S, Chakrabarti S, Mattoo SK, Avasthi A. Symptom profile of delirium in children and adolescent - does it differ from adults and elderly? General Hospital Psychiatry. 2012;34:262-632.

14.          Day J, Higgins I. Existential absence: The lived experience of family members during their older loved one’s delirium. . Qualitative Health Research. 2015.

15.          Breitbart W, Gibson C, Tremblay A. The delirium experience: Delirium recall and delirium-related distress in hospitalised patients with cancer, their spouses/caregivers, and their nurses. Psychosomatics. 2002;43(3):183-94.

16.          Gagnon P, Charbonneau C, Allard P, Soulard C, Dumont S, Fillion L. Delirium in advanced cancer: A psychoeducational intervention for family caregivers. Journal of Palliative Care. 2002;18(4):253-61.

17.          Lipowski ZJ. Delirium: Acute confusional states. New York: Oxford University Press; 1990.

18.          Day J, Higgins I. Adult family member experiences during an older loved one's delirium: a narrative literature review. Journal of Clinical Nursing. 2015:n/a-n/a.

19.          Andersson E, Knutsson I, Hallberg I, Norberg A. The experience of being confused: A case study. Geriatric Nursing. 1993;14(5):242-7.

20.          Fagerberg I, Jönhagen ME. Temporary confusion: A fearful experience. Journal of Psychiatric & Mental Health Nursing. 2002;9(3):339-46.

21.          McCurren C, Cronin SN. Delirium: Elders tell their stories and guide nursing practice. MEDSURG Nursing. 2003;12(5):318-23.

22.          Sorensen Duppils G, Wikblad K. Patients' experiences of being delirious. Journal of Clinical Nursing. 2007;16(5):810-8.

23.          Andersson E, Norberg A, Hallberg I. Acute confusional episodes in elderly orthopaedic patients: The patients' actions and speech. International Journal of Nursing Studies. 2002;39:303-17.

24.          Andersson E, Hallberg I, Norberg A, Edberg A. The meaning of acute confusional state from the perspective of elderly patients. International Journal of Geriatric Psychiatry. 2002;17(7):652-63.

25.          Harding R, Martin C, Holmes J. Dazed and confused: Making sense of delirium after hip fracture. International Journal of Geriatric Psychiatry. 2008;23(9):984-6.

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