Delirium is a serious condition which causes a sudden change in how a person thinks and behaves. It affects about 20 in 100 (20%) of adults admitted to hospital and 35 in 100 (35%) of adults admitted to hospices. It becomes more common as people approach the end of life.
Delirium causes an increased risk of falls and pressure sores. It can also cause longer hospital stays and increased mortality. It can be distressing for the person with delirium and those close to them. But there are ways that you can help.
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Key points
- Delirium is a serious and distressing condition.
- Identifying delirium early is important because it increases the person's chance of recovery from delirium and it helps us provide better care for the person with delirium and those close to them.
- Using a delirium detection tool helps healthcare professionals to detect delirium.
- If someone has delirium, use the term 'delirium', rather than non-specific words like 'confusion'.
- Delirium may have more than one cause.
- Many people will recover from delirium if the underlying causes are treated.
- Towards the end of life, people may not recover from their delirium, and healthcare professionals should focus on making them comfortable.
- Remember to offer explanation and support to families and suggest how they can help.
- Only use medicines if the person with delirium is very distressed, and other strategies have not helped.
Watch: Caring for someone with deliriumWatch: Caring for someone with delirium
This video for health and social care professionals explains what delirium is, how to recognise it, and how it’s treated.
Understanding delirium
Delirium usually starts suddenly over hours or days. It's a sign that the person is physically unwell.
Delirium may cause a person to:
- feel confused and develop problems with their memory
- feel disorientated – not know where they are or what time of day it is, or recognise the people around them
- have difficulty talking and understanding what people say to them
- find it difficult to concentrate
- say or do things that are out of character
- experience auditory or visual hallucinations
- think that people are trying to harm them.
Symptoms of delirium may come and go, and sometimes get worse at night.
It is not always possible to prevent delirium, but steps can be taken to reduce the chance of a person developing delirium. Many of these preventative strategies are also helpful in treating delirium (see Treating delirium – Ways to support people with delirium below).
Delirium and dementia
Delirium can sometimes be mistaken for dementia. While there may be a few similarities, dementia is a different condition. Dementia develops over months or years, compared to hours or days with delirium.
People living with dementia are more at risk of developing delirium. So, if you notice a sudden change in how a person with dementia thinks or behaves, consider delirium as a possible cause. Seek advice from the person's doctor or nurse as soon as possible. Or ask a senior colleague or dementia specialist for support in confirming the diagnosis.
Types of delirium
There are 3 types of delirium:
- Hyperactive delirium is when the person is anxious, restless or agitated.
- Hypoactive delirium is when the person seems sad, withdrawn, and drowsy.
- A person with mixed delirium has symptoms which fluctuate between hyperactive and hypoactive delirium.
Hypoactive delirium is the most common type of delirium to affect people living with terminal illness. Of people with delirium, about 40 in 100 (40%) will have the hypoactive type, compared to 15 in 100 (15%) with hyperactive delirium.
Hypoactive delirium can be more difficult to recognise than hyperactive and mixed delirium. This is because it's sometimes mistaken for the person being very tired, or having depression or dementia.
Causes of delirium
Many conditions can cause delirium. Causes may include:
- having an infection
- being dehydrated
- having poorly controlled pain
- being constipated or in urinary retention
- liver or renal failure
- electrolyte imbalances like hypercalcaemia (high levels of calcium in the blood) or hypoglycaemia (low blood glucose levels)
- hypoxia (low oxygen levels)
- medicines, especially sedatives or strong analgesics
- having surgery
- having a stroke
- withdrawal from medicines and alcohol.
Anyone can develop delirium, but some people are more at risk.
People at higher risk of developing delirium are:
- people who are approaching the end of their life
- older adults
- people with hearing or sight loss
- people with dementia
- people with depression or other psychiatric illnesses
- people who are on lots of medicines or have several health problems.
Identifying delirium
Delirium often goes undiagnosed and under-treated. Identifying delirium early is important, as it improves the chance of the person getting better. It will also help you provide better care for the person with delirium and the people who're important to them.
If you, or people close to them, are concerned about a recent change in how the person thinks or behaves, consider delirium as a possible cause. Arrange for them to be assessed as soon as possible by their doctor or nurse.
The 4 'A's test or 4AT
Clinical guidance and best practice recommend using delirium detection tools. The tools can help healthcare professionals to detect delirium, on top of using their clinical judgment.
The 4'A's test or 4AT is a short and simple 4-item delirium detection tool. It's used by healthcare professionals:
- when delirium is suspected or
- to check or screen for delirium when people move to a new place of care, such as a hospital or care home.
You do not need special training before using this tool, but it's helpful to have some knowledge of delirium.
The 4AT takes a few minutes to complete. All patients can be tested, even those too sleepy or agitated to answer questions. If the 4AT suggests the person has delirium, ask the person's doctor or nurse, or a senior colleague, for further assessment to confirm the diagnosis.
If you do not feel confident using the 4AT, ask a senior colleague for support.
Treating delirium
If a person is diagnosed with delirium, remember to use the term 'delirium' when communicating with others, rather than non-specific words like 'confusion.' This helps shared understanding and encourages better care for the person with delirium.
The treatment of delirium will depend on the cause of the person's delirium, their health and their preferences for care.
Treating the underlying causes of delirium
Delirium usually improves if healthcare professionals can find and treat the underlying causes. For example, giving antibiotics for an infection, encouraging the person to drink more fluids if they're dehydrated, or reviewing their medication.
Delirium may have more than one cause.
Ways to support people with delirium
Ensuring a calm and supportive environment is also important to help the person recover from their delirium and feel less distressed. Some of these actions may also reduce the risk of delirium developing.
Here are some recommendations for healthcare professionals.
Engage with family, friends and other people close to the person with delirium
People close to the person with delirium will know what brings them comfort and reassurance. You could ask them:
- whether the person uses glasses, hearing aids, or any other accessibility tools
- to bring in or keep nearby familiar photos or favourite items, to help engage with the person
- what the person's favourite music or sounds are
- to stay nearby as much as possible – especially if they are in an unfamiliar place, or less familiar people, like healthcare staff, are also in the room.
Practice good communication
- Talk in simple sentences about familiar things.
- Try to speak clearly and softly. Check that they understand you.
- If they find it difficult to talk, ask simple questions where they can give "yes" or "no" answers. Consider asking 'do you feel frightened' or 'are you in pain.'
- If they're distressed, try to find out and address what's causing this – for example, are they in pain, thirsty, worried or constipated?
- If they believe things that are not true, or are worried that someone is trying to harm them, reassure them and let them know they are safe.
Look after their health and wellbeing
- Keep their environment as calm as possible – avoid loud noises and too many visitors.
- Help keep them orientated. Have a clock nearby.
- Help them to drink and eat.
- Support them to remain active – help them to sit up or move around safely. Read more about how to help someone to walk, sit and stand up using the link below.
- If they cannot go outside, offer to take them near a window to get some daylight.
- Help prevent them from developing pressure sores. Read more about pressure damage using the link below.
- Help them maintain a good sleep pattern. For example, have a bedtime routine and dim the lights at nighttime.
- Avoid caffeinated drinks after lunchtime, as these can affect sleep. Offer decaffeinated drinks instead, such as water or squash.
- If the person is in hospital, try to avoid moving them to different wards.
Pharmacological treatment of delirium
Medicines such as antipsychotics and benzodiazepines can be used to treat delirium-related distress. But these should only be used if the person is very distressed and other strategies have not helped. This is because these medicines can worsen delirium and cause other adverse effects. If medicines are needed, healthcare professionals should review these regularly, and withdraw them as soon as the person recovers.
What if a person with delirium is unable to make decisions about their care?
Delirium may cause a person to lose the ability or capacity to make decisions about their own care. If this happens, decisions should be made in the person's best interest, following the relevant legislation – The Mental Capacity Act (2005) in England and Wales and Adults with Incapacity Act (2010) in Scotland.
Delirium towards the end of life
Many people will recover from delirium. But this may not always happen if the person is approaching the end of life. Towards the end of life, healthcare professionals should focus on ensuring the person is comfortable and manage their symptoms.
Agitation can be a symptom of delirium. But agitation may be caused by other problems, such as pain, breathlessness, constipation or being in urinary retention. It's important to find out what's causing the distress and address it, if possible.
Delirium causing agitation in the last hours or days of life is sometimes called terminal agitation. The person may groan or shout in a confused way. They may be restless, fidgety, pull at their bedcovers, or try to get out of bed when it's unsafe for them to do so. Medicines, such as antipsychotics and benzodiazepines, may be needed to ensure the person remains calm and comfortable.
Recovery from delirium
Recovery from delirium may take a few days. But for others, recovery may take longer. Many people will get better once the underlying cause of delirium is treated, if they're not approaching the end of their life.
After recovering from delirium, some people remember hallucinations and delusions. They may experience ongoing problems with their mental wellbeing. Remember to check with the person and those close to them to see if they have concerns or need support.
Supporting people close to the person with delirium
It can be distressing for family and friends to see someone experience delirium. You can help by explaining about delirium and offering them support.
You can show them how to help the person with delirium by making them feel orientated and comfortable (see Treating delirum – Ways to support people with delirium above).
