What is delirium?

Ben Budd
January 26, 2022
November 20, 2023

As well as the person living with dementia, delirium can have a major impact on carers. It is really important to ensure carers are given the knowledge of what to look for, how to respond and importantly, to prevent it from happening or recurring. Carers play a vital role from treatment to prevention of delirium.

What is delirium?

The UK has an increasing population of older people and many will be at risk of developing multiple health conditions. The combination of multiple health conditions, frailty and dementia or cognitive decline, can put the person at very high risk of developing delirium.

“Delirium” or “acute confusion” is a state of rapid, intense mental confusion that can happen to anyone if they become severely unwell. It happens suddenly, within hours or days, and it can be very frightening for both the person and carers who are supporting them. If not addressed early, delirium can have an adverse outcome for the person with dementia.

This video is really helpful in explaining delirium.

There are various types of delirium

Hyperactive Delirium

This type of delirium is the most obvious with very clear, sudden and major changes to the person experiencing it.

The person may be agitated and display hyperactive behaviours (being unusually or abnormally active). These may include hyper-vigilance, restlessness, rambling speech, loud vocalisations, hallucinations, increased motor activity, wandering, distractibility, irritability and low tolerance for frustrations.

Due to confusion and fear they may become defensive and can respond by verbally or physically threatening those trying to help

Hypoactive Delirium

This is much less obvious than in hyperactive delirium. Hypoactive (a decrease in behavioral or physical activity) can often be mistaken for depression or dementia or a decline in a person who already has an existing dementia. It has poorer outcomes for the person if not treated swiftly.

The person will appear drowsy and inactive. There will be decreased speed of activity and speech, reduced awareness of surroundings.

Mixed Delirium

There are alternating features between the hyper and hyp-oactive types. In this instance the patient may switch between both hyper and hypo delirium features

The common risk factors and triggers for delirium

The difference between delirium and dementia?

This is not always straightforward even for professionals, as you may be seeing a delirium superimposed on dementia. Below are some comparisons that may be helpful to differentiate them from each other.

How is delirium treated and managed?

If you suspect delirium, then assessment and appropriate tests should be carried out as soon as possible.

There can be multiple triggers/causes which can make diagnosis and treatment complex, and this may take some time, so the earlier you seek help the better the outcome for the person.

Once the cause is identified and treated the delirium will usually resolve, however recovery time is different for each person and in some cases the symptoms may persist for up to six months.

A person with dementia has more challenges as the disease process may already be compromising brain function therefore, they may take more time to recover.

Delirium diagnosed in hospital

If delirium is diagnosed in hospital it is really important to ensure the persons GP is informed of the diagnosis. GPs may may need to provide community follow up and monitor the situation.

After an initial episode of delirium, it is very beneficial to initiate a Prevention Plan to ensure you identify any early warning signs, treat quickly and prevent escalation. Speak with the hospital staff, your local GP or Community Mental Health Team who may have specific Care Plans in place already.

Impact on you as a carer

As a carer, delirium can have a major impact on you also and you may need to enlist other members of the family or friends for support.

Knowledge really is power in these circumstances. So, ensure you are given appropriate information, you are kept informed, ask questions, make your needs known by asking for a carers assessment and don’t be afraid raise your concerns, your loved one may not be able to.

More support online

The Live Online Learning session: ‘Caring about sudden or extreme confusion (delirium)’ explores this issues in more depth. Led by registered health and care professionals, the online zoom sessions support carers difficult life events. These sessions help family carers to feel as prepared and supported as possible and there is time to connect with other carers as well as the professionals in a supportive and protected environment.


National Institute for Clinical Care Excellence (NICE) – Delirium prevention diagnosis and management (updated 2019)

Royal College of Nursing (RCN)

Scottish Intercollegiate: Guidelines Network (SIGN): Risk Reduction and Management of Delirium (2019)

Scottish Delirium Association (SDA) (2014). Delirium Toolkit

Health Improvement Scotland

By Lorraine Haining, Queens Nurse based in Dumfries and Galloway in Scotland

Lorraine Haining‘s background is in nursing and she has specialised in dementia care for the past twenty years. She’s one of the 41 community nurses in Scotland who hold the title of Queens Nurse. Lorraine enjoys the education arm of her work and knows acquiring knowledge and skills can be really empowering for family carers.

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