Delirium in the elderly
How to recognise sudden confusion (delirium) in older adults
Your health expert: Fran Vandelli, Dementia Lead, Bupa Care Services
Publish date 05/03/2025
Next review 12/03/2028
Together with Fran Vandelli, Dementia Lead at Bupa Care Services, we explore potential causes of delirium, how it can be linked with health conditions affecting older people and why it’s surged in search interest.
What do the search engines say?
Our research shows that more and more people are searching for information about delirium and how it can present in elderly friends and family members.
Between October 2023 and September 2024, the following Google search terms doubled in popularity:
Delirium meaning
UTI signs and symptoms
Early signs and symptoms of UTI
We’ve also seen the following Google search terms reach a four-year high:
UTI in elderly
Symptoms of UTI in elderly
Delirium and elderly
What is delirium?
Delirium is a sudden, temporary change in a person’s mental state. It can come about very quickly, often leading to confusion, poor focus and drowsiness. It’s causes include:
- Chest infections
- Urinary tract infections (UTIs)
- Dehydration
- Medication side effects.
Delirium is a temporary, treatable state. However it can last a long time. Having delirium once can increase the risk of it happening again.
Delirium, depression and dementia may sometimes be mistaken for each other, as they can cause similar symptoms. However, it’s important to know that delirium and dementia are two very different conditions.
What’s the difference between delirium and dementia?
Delirium and dementia both cause confusion, but they are different. Here are the most important differences between them.
Delirium
- Temporary, caused by an underlying memory issue
- Comes on suddenly, over hours or days
- Triggered by infections, medications or dehydration
Dementia
- Permanent
- Develops slowly over months and years
- Caused by brain disorders such as Alzheimer’s
It's important to note that dementia increases the risk of delirium. A person with dementia, might experience delirium when they face an infection or other stressor like hospitalisation. The similarity in symptoms can make it harder for care givers to distinguish between the two conditions, as the symptoms can seem similar.
What are the symptoms of delirium?
Confusion
Struggling to focus
Drowsiness
Agitation
Change in memory and sleep patterns
Mood swings
Delusions
Rambling speech
A note for friends and loved ones about diagnosing delirium
Recognising the signs of delirium in the elderly is important for getting the right treatment quickly. Friends and carers, who know the person well, are often better at noticing when an older person isn’t acting like themselves. Without knowing the symptoms of delirium, it may easily be confused with other conditions, including depression or dementia.
Health professionals, who’ve only met the person for the first time, may not know what’s usual behaviour for them. This can make delirium harder to spot and diagnose. If your loved one is misdiagnosed and given unsuitable medication, it could make their delirium worse.
Your knowledge of your loved one can help inform the diagnosis. If you can, you should try to go with them to diagnosis appointments.
Are we seeing more dementia cases?
The chance of developing dementia increases with age. As our population lives longer, we’re seeing more people affected by dementia and periods of delirium. This is often associated with forgetting to drink, or finding it harder to care for yourself.
The older generation may be more prone to loneliness. Social isolation can be another influencing factor leading to cognitive decline. This is especially true in winter, when older adults may have fewer social interactions and spend long periods indoors.
Loneliness has been linked to cognitive decline and a weakened immune system. This may make infections and delirium more likely.
Do over 65s struggle more with delirium?
Several factors may be leading to an increase in delirium in older adults.
An ageing population
The UK’s population of people aged 65 and over continues to grow. Age is a major risk factor for both dementia and delirium.
As our ageing population increases, more families are encountering these conditions. This leads them to look for for answers and help online.
Winter months
Winter consistently sees a spike in delirium related cases. Older adults are more vulnerable to developing infections like colds and flu.
A weakened immune system can make it harder to fight off harmful bacteria, which can increase the risk of urinary tract infections (UTIs).
UTIs are a common trigger for delirium, and can cause confusion and disorientation.
Dehydration
Older adults are at higher risk of dehydration. This is because the amount of water in the body and sense of thirst declines with age. The risk of developing some health conditions, like high blood pressure and diabetes, can also increase with age.
Medication used to manage these conditions may also increase the risk of dehydration. Older people with neurological conditions, like dementia, may find it more difficult to remember to drink regularly. This can increase their risk of contracting infections, and developing delirium as a side effect.
Why do UTIs cause delirium in adults?
When coping with a UTI, your immune system works to fight the inflammatory response that causes fever-like symptoms. Older adults – especially those with dementia - are more affected by these changes, and this can lead to confusion and delirium.
UTIs can be difficult to spot in older adults. This is because they may not always communicate how they’re feeling, especially if they have cognitive impairments like dementia. It’s important for carers and family members to recognise unusual behaviours as a potential sign of infection. If you do spot these signs, make sure you seek help from a health professional.
Untreated UTIs can lead to more severe health issues, and can sometimes speed up the progression of dementia. If an older person, or someone with dementia, suddenly becomes confused or their behaviour changes without explanation, it’s important to consider a UTI as a possible cause and raise this with a health professional.
Preventing delirium in older adults
Delirium can be prevented in around a third of cases by tackling the potential causes.
To help reduce the risk of delirium, families and carers can:
- Encourage the person to drink enough water to stay hydrated each day
- Reduce intake of alcohol to make sure the weekly recommended quantity isn’t exceeded
- Watch out for early signs of UTIs or viral infections, especially during winter
- Speak to health professionals about medications if you suspect they may be causing side effects
- Maintain consistency in their daily routine and surroundings
- Encourage them to eat balanced meals with enough vitamins and minerals.
Families can also help by:
- Bringing a familiar item when visiting, like photos or a favourite keepsake. This can make them feel more at ease.
- Helping them stay active, if it’s safe, to avoid physical decline
- Sharing details of their usual routine and preferences with carers and/or staff.
When to seek help for delirium
Delirium is a medical emergency that needs prompt attention. If you suspect an older adult is experiencing delirium, don’t delay in getting help and treatment. Early intervention can prevent complications and improve recovery.
For ongoing confusion or memory problems, it’s important to discuss concerns with a health professional. This can help determine whether the cause is delirium, dementia, or something else.
By understanding the differences and causes of these conditions, we can better support our loved ones and ensure they’re receiving the right care.
