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Delirium is a state of mental confusion. Delirium is not a disease, but a group of symptoms that can be caused by other medical problems.
Delirium can start very suddenly, sometimes in just a few hours. Delirium is very common, particularly in older people and people treated in hospital.
Delirium is not the same as dementia, and it can be treated.
There are three types of delirium: hyperactive delirium, hypoactive delirium, and mixed delirium.
The symptoms of someone with hyperactive delirium include:
The symptoms of someone with hypoactive delirium include:
Mixed delirium means that someone can switch between symptoms of hyperactive delirium and hypoactive delirium, sometimes over the course of a day.
Medical problems that can cause delirium include:
Delirium can often be caused by more than one of these things, and sometimes the cause is never found. Someone is also more likely to get delirium if they:
If someone with dementia has delirium, there will be a sudden, noticeable change in their usual behaviour. This is most often noticed by family members or carers, who know what is normal for that person.
Someone who has dementia and delirium may do things that are out of character: for example, they may not usually be aggressive, but suddenly start behaving aggressively if they have delirium.
Yes. Delirium is preventable and treatable.
Doctors treat delirium by treating the cause of the delirium. For example, if a medicine is causing delirium, the doctor will stop or change that medicine. If an infection is causing delirium, they will treat the infection.
Sometimes, in older people, the effects of delirium can last a bit longer even after the cause is treated, even weeks or months. Remembering the delirium can also be upsetting and frightening for that person.
The earlier that delirium is identified and treated, the better the outcome for that person.
You can help someone by:
Sometimes the signs of delirium can be difficult to spot. This checklist can help you if you are not sure if someone has delirium.
Are they confused?
Do they lose focus?
Are they having distressing thoughts?
Are they restless?
Are they lethargic?
Are they being aggressive?
Have they had one or more falls?
Are they eating and drinking a normal amount for them?
Are they experiencing hallucinations?
Have these changes come on suddenly, over hours or days?
If that person is in hospital, speak to the nurse or medical professional looking after them. If they are not in hospital, contact your GP.
The earlier that medical staff recognise delirium and treat it, the better. Don’t be afraid to tell someone if you are worried.
This information is intended for patients receiving care in Brighton & Hove or Haywards Heath.
The information in this leaflet is for guidance purposes only and is in no way intended to replace professional clinical advice by a qualified practitioner.
Publication Date: June 2022
Review Date: March 2025