The information in this page is for patients who have been diagnosed with delirium. Family members and carers may also find this information useful.

What is delirium?

Delirium is a worsening or change in a person’s mental state that happens suddenly. It is sometimes referred to as an ‘acute confusional state’.

Delirium is a sign that the person has something wrong. It can happen when the person has an infection, is dehydrated or in pain. Having an operation and being constipated are also physical conditions which can lead to delirium.

Delirium can come on suddenly and does not usually improve until the persons physical condition improves. Sometimes it can take a few months after the physical condition has improved for the person to get back to their normal mental state.

What causes delirium?

Almost anything can trigger delirium. The most common causes are:

  • Pain
  • Infections
  • Nutrition (not eating enough)
  • Constipation
  • Dehydration
  • Medications (especially diuretics, antidepressants, pain relief and medications for Parkinson’s disease)
  • Changes in surroundings and routine

How common is delirium?

About 1 in 10 hospital patients aged 70 and under, may experience a period of delirium. However, people over the age of 70 years with other underlying health conditions, for example raised blood pressure or dementia, their risk of experiencing delirium can rise to up to 1 in every 3 patients.

Who might experience delirium?

Anyone can develop delirium. However, you are more likely to develop delirium if you:

  • are over 65 years old
  • have a hip fracture
  • have a serious illness
  • have any kind of memory problem

It is also more common in people who:

  • are living with dementia
  • have a sight or hearing impairment
  • are taking multiple medications
  • are frail (have existing health needs which might affect their ability to recover from any new health need)
  • experience poor sleep
  • drink excessive amounts of alcohol
  • have experienced delirium before

What is it like to have delirium?

People with delirium are less aware of what is going on around them. Their mood may change quickly and they might be confused about days and times.

Delirium is usually split into 3 types:

  • Hyperactive - this means the person is restless and distressed. They might hear voices or see things that are not real.
  • Hypoactive - with this type of delirium the person may be sleepy and need prompting to eat and drink or attend to their personal care.
  • Mixed - someone with a mixed delirium may experience all of the hyperactive and hypoactive symptoms at different times. It can be quite frightening for the person, particularly if they are hearing voices or seeing things that are not real.

Having delirium is a serious complication to another medical illness and can lead to other problems which can put the person at risk of injury and premature death. Early recognition that the person has developed delirium is important.

How is delirium diagnosed?

The patient may have blood tests, scans or X-rays to find out why they are ill but currently there is no test for delirium. The diagnosis is made through assessing how the person is behaving when they are examined. The examination will be performed by a clinician.

Hospital staff will want to talk to someone who knows the patient well to find out whether any confusion or unusual behaviour is normal for the patient.

Reducing the risk of delirium

We try to reduce risks of developing delirium by:

  • Minimising ward or bed moves for the person.
  • Treating physical illnesses as quickly as possible.
  • Making sure that the patient is aware of the ward layout and routine.
  • Keeping the ward as calm and quiet as possible.
  • Having a limited number of nurses caring for each patient.
  • Providing reassurance to the person, by reminding them of where they are and what the date, day and time is.
  • Providing caring and regular nursing support.
  • Avoiding the use of urine catheters unless essential; these can increase the chances of infection which may lead to delirium.

How can family and carers help?

  • Let staff know if your relative has suffered with delirium before.
  • Listen - sometimes, as a person improves, they start to understand and remember what was happening to them which they may want to talk about.
  • Bring in dentures, reading glasses and hearing aids (label them if possible).
  • Visit and be involved in supporting your relative as often as you are able. We offer open visiting and support ‘John’s Campaign’. Visit for more information.
  • Bring in a completed copy of the ‘This is me’ document. This can be downloaded from the Alzheimer’s Society website: On this page you will also have the option to order a free copy by post.
  • Bring in some familiar items to make the person feel more at home (label them if possible). We do our best to keep things safe, but please do not bring anything valuable or irreplaceable. A small clock, table top calendar and photos of family are very useful.

Treating delirium

Finding and treating the physical cause, is the best management of delirium. It is important for the person with delirium to be reassessed often.

People with delirium may be referred to the Mental Health Liaison Team who assess and treat patients with mental health needs.

When patients are very agitated or distressed, they often pose a risk to themselves or other people such as falling over or aggressive behaviour. In these circumstances it may help if the person is treated with medication such as haloperidol (antipsychotic).

The medication is to help keep the patient safe and will allow the patient to recover more quickly. Other sedative medications may be considered but these will not treat the actual delirium.

Delirium and capacity

Delirium can often affect a person’s ability to understand information and make decisions (capacity). This will be assessed regularly by the person’s medical and nursing team.

When a person with delirium is unable to give consent, the Trust will introduce a plan of care in their best interest. This decision will usually involve the family and carers. In an emergency situation we may need to sedate the person to carry out vital treatment.

Follow-up care after discharge from hospital

It is important that a person who has experienced or is experiencing delirium does not drive until all their symptoms have stopped and they have been reviewed by their GP and advised that they are safe to drive.

The diagnosis of delirium in hospital will be shared with the persons GP along with other discharge information (including medication when discharged). This will support the GP in managing and assessing the person after discharge.

Further information

If you would like more information about delirium, or if you have any questions, please ask the nurse in charge of the ward or the ward doctor.

You can also find helpful information about delirium at the following websites:



Alzheimer’s Society


Dementia UK


Printable version of this page

Delirium GHPI1174_11_23 Department: Care of the Elderly Review due: November 2026 PDF, 342.3 KB, 6 pages
Reference number GHPI1174_11_23
Department Care of the Elderly
Review due November 2026