Delirium in older people: signs, causes and how to help

Delirium is a sudden change in a person’s attention, awareness or thinking. It can be frightening for the person and those around them, but it is not a normal part of ageing. It often develops over hours or days and may fluctuate. A person can have delirium alongside dementia, but a sudden change should not simply be put down to dementia or old age. If you notice a new or marked change, contact a health professional promptly.

This guide is general information, not a diagnosis or a substitute for medical care. Delirium can have different causes, and a clinician needs to assess the person and decide what is happening.

Signs to look for

The changes may be subtle at first, and they can be different from one person to another. Look for a clear change from your relative’s usual behaviour or abilities, such as:

• Trouble paying attention, following a conversation or staying focused.
• Confusion about where they are, the time or what is happening.
• Speech that is unusually muddled, or difficulty finding words.
• Seeing or hearing things that others do not, or becoming unusually suspicious or distressed.
• Restlessness, agitation or trying to leave a place unexpectedly.
• Unusual drowsiness, reduced movement, or being difficult to engage. This quieter form can be missed because the person may not seem disruptive.
• Changes that come and go, sometimes becoming more noticeable later in the day or at night.

The NHS overview of delirium describes delirium as confusion that can start suddenly and change over time. If you are unsure whether a change is significant, compare it with what is usual for your relative and describe what you have noticed to a clinician.

Possible causes and triggers

Delirium is often associated with an underlying health problem or a change in the person’s circumstances. Possible contributors include an infection, dehydration, pain, constipation, difficulty passing urine, poor sleep, a recent operation or hospital stay, or changes in medicines. Several factors may be involved at once. A new environment, reduced hearing or vision, and unfamiliar routines can also make it harder for someone to stay oriented.

This list cannot identify the cause in an individual. Don’t start, stop or change medicines based on this guide. Share a complete, current medication list with the clinician, including non-prescription products if you know them. Tell them about recent changes, missed doses, illness, falls, pain, eating and drinking, sleep, and the timing of the symptoms. A Carer's daily log generator can help you organise observations to share.

What to expect over time

Delirium does not follow a reliable set of stages, and there is no single recovery timetable. It may begin quickly, fluctuate during the day, and look different from one day to the next. Some people become restless; others are quiet or sleepy. Their abilities may vary, so a conversation or task that was manageable earlier might be difficult later.

After the cause has been assessed and care is underway, improvement may be gradual. Confusion, tiredness or changes in attention can continue for a while, and the person may need extra help with familiar tasks. Keep following up with the care team if symptoms persist, worsen or return. If your relative already has dementia, it can take time to understand what has changed from their usual level of functioning.

How to help at home

Your calm, familiar presence can be reassuring. Try these practical steps while arranging and following professional advice:

• Speak simply and gently. Use short sentences, introduce yourself if needed, and give the person time to respond. Offer reassurance rather than arguing about what they believe or remember.
• Help them stay oriented. Remind them where they are and what is happening in a calm way. A clock, calendar, familiar photographs and familiar belongings may help. Repeating the same explanation can be kinder than testing their memory.
• Keep the surroundings familiar and manageable. Reduce unnecessary noise and visitors if these seem overwhelming. Support the person to use their usual glasses or hearing aids if available.
• Keep a steady routine. Offer familiar meals, drinks and activities as appropriate. Encourage rest at night and gentle daytime activity if it is safe for them. Don’t force food or drink; ask the care team for guidance if swallowing or intake is a concern.
• Make everyday movement safer. Stay nearby if the person is unsteady or confused about where they are. Clear walkways and remove obvious trip hazards. A home safety checklist can help you review the home. Don’t use physical restraint; if you cannot keep someone safe, contact local urgent or emergency services for guidance.
• Keep notes. Record when changes started, how they vary, what the person was doing, and any relevant changes in health or routine. Share the notes with clinicians rather than trying to work out the cause yourself.

You can also use a Carer's daily log to note changes and a Care visit handover form to pass on key information when family or other helpers take a turn.

When to call a GP or emergency services

A sudden change in confusion or alertness needs prompt medical assessment. Contact a GP, urgent medical service or local health advice line as soon as possible, and explain that the change is new. If the person is already in hospital or a care setting, tell staff straight away. The NICE delirium guideline advises health professionals to look for delirium when there are recent changes in cognition, perception or behaviour.

Use your local emergency number if the person is unresponsive, has severe difficulty breathing, has a serious injury, or you believe they are in immediate danger. Don’t wait for a routine appointment in an emergency. If you are uncertain how urgently help is needed, contact a local health professional or emergency advice service and describe the changes.

For an assessment, it may help to have the person’s medical history, current medicines, allergies if known, and an emergency contact ready. A older person’s emergency information sheet can keep key details together. Don’t delay seeking care in order to complete paperwork.

Looking after yourself and sharing care

Supporting someone who is confused can be exhausting, especially when symptoms change from hour to hour or interrupt sleep. Ask another trusted person to take a defined shift, make calls or prepare food. If you can, step away for a short break while someone reliable stays with your relative. Be honest with the care team about what you can safely manage at home and ask what local support is available.

If delirium begins during a hospital stay, ask staff what changes they have noticed, what the plan is, and who to contact if symptoms continue after discharge. Write down instructions and arrange a handover with anyone helping at home. Recovery may take time, so regular check-ins and realistic shared responsibilities matter. The Alzheimer’s Society guide to delirium also explains that delirium can occur in people living with dementia. Remember: you do not have to manage sudden confusion alone.