Does dementia kill you? Understanding dementia life expectancy

When someone receives a dementia diagnosis, they may ask “Does dementia kill you and how does dementia kill you?” This article highlights dementia life expectancy, helps you understand how the condition progresses, how to reduce risks and helps you or your relative get the best care.

Key Points

• Dementia is terminal, but death usually results from complications rather than the condition itself.
• Serious complications include pneumonia, falls, infections, weight loss, dehydration and organ failure.
• The condition progresses from mild memory problems to severe mobility issues and swallowing difficulties requiring full-time care. These have been referred to the 7 of stages of dementia before death.
• Risks can be reduced with monitoring, safe home adjustments, nutrition support and professional dementia care.

How does dementia kill you?

Dementia affects nearly a million people in the UK. Some wonder how does dementia kill you.

Dementia itself is not usually listed as the immediate cause of death, but it is a terminal condition because it gradually damages the parts of the brain responsible for essential functions such as memory, movement, swallowing and communication.

Alzheimer’s Research states that as dementia progresses, ‘damage to the brain spreads, eventually reaching the brainstem.

‘The brainstem forms the connection between the brain and spinal cord and is responsible for controlling vital functions like breathing and swallowing.’

As dementia progresses, it can lead to serious complications, including:

1. Infections

People with advanced dementia may have difficulty swallowing, which can cause food or liquid to enter the lungs. This increases the risk of aspiration pneumonia which is a type of pneumonia caused by food or drink going down the windpipe instead of the food pipe. This is one of the most common causes of death in people with dementia.

2. Falls and injuries

Memory loss, reduced balance and confusion make falls more likely. Fractures or head injuries can have serious consequences.

Alzheimer’s Research UK states ‘After a fall, as well as pneumonia, people with dementia are also more likely to experience sepsis and surgical site bleeding than people without dementia’.

3. Severe weight loss and dehydration

In late-stage dementia, someone may not eat or drink, leading to malnutrition and dehydration.

They may have a loss of appetite caused by damage to the part of the brain that controls hunger and thirst.

It could be that they forget to eat, because of damage to the memory centres of the brain.

They may struggle to chew and swallow caused by damage to the brainstem.

4. Reduced immune function

As the condition progresses, the body becomes more vulnerable to infections such as urinary tract infections (UTIs) or sepsis.

Alzheimer’s Research states, ‘as dementia progresses, many people develop problems with incontinence’ and ‘struggle to maintain personal hygiene’, forgetting to change their clothes or wash regularly.

‘These things can lead to a build-up of bacteria in the urinary tract, leading to symptoms like a fever and a burning sensation when using the toilet.

Dehydration can also increase the risk of UTIs, as going the toilet less often reduces the number of times that bacteria are flushed out of the body’.

5. Organ failure

Damage to the brain eventually disrupts essential bodily functions, which can lead to organ failure.

How long can someone live with dementia?

Life expectancy depends on many factors, including age, general health and the type of dementia.

Understanding the stages of dementia

While every person’s journey is different.

You may have heard that there are 7 stages of dementia before death.

The Global Deterioration Scale was developed by Dr Barry Reisberg and outlines seven different stages of how dementia progresses.

7 stages of dementia

The so-called 7 stages of dementia before death are:

Stage 1 No memory loss or impaired brain function

No signs of the condition.

Stage 2 Very mild cognitive decline

First signs of memory issues. E.g. briefly forgetting names.

Stage 3  Mild cognitive impairment

Symptoms noticeable to family and friends.

e.g difficulty finding familiar places and getting lost walking/driving to a shop they know.

Forgetting or mixing up the names of relatives or other loved ones.

Finding it difficult to remember the ‘right’ word when speaking.

Reading but struggling to retain any of the information.

Stage 4 Mild dementia

Usually can be diagnosed at stage 4 through tests or interviews.

They may find it difficult to organise things, such as a trip.

Poor memory of events that have happened in their own lives.

Less able to do tasks like paying bills.

Stage 5 Moderate Dementia

The person will start to require help with daily life.  

Stage 6 Moderately severe dementia

Constant supervision is likely required and personality changes may happen.

Stage 7 Severe dementia

In the final stage of dementia, the person will require help with toileting, washing, eating and other daily activities. Motor skills are expected to deteriorate, leaving the person unable to walk unaided.

24/7 hour care will be required.

A person with dementia may not experience all 7 stages. They may die before the 7^th stage.   

These 7 stages can be put into three stages; early stage, mid stage and late stage. 

Early Stage

• Mild memory problems
• Difficulty concentrating.
• Able to live fairly independently.

Middle Stage

• Increasing confusion.
• Greater support needed with daily tasks.
• Behavioural changes.

Late Stage

• Reduced mobility.
• Difficulty swallowing.
• Full-time personal care needed.

So, does dementia kill you?

It is usually the complications of late-stage dementia that leads to death, not the diagnosis itself.

With compassionate support and careful monitoring, many risks can be reduced, helping people live comfortably and safely.

What matters most is receiving consistent, compassionate support that maintains quality of life for as long as possible.

Dementia life expectancy

On the subject of dementia life expectancy, the life span of a person who has been diagnosed with dementia can be 10 years. It can be longer depending on a person’s symptoms and age.

Is there a cure for dementia?

While there is no cure for dementia there are dementia treatments available. 

What treatments are available for dementia?

Dementia treatments include:

Anti-amyloid drugs (donanemab & lecanemab) are approved in the UK but are not available on the NHS

Anti-dementia drugs (donepezil, rivastigmine, galantamine, memantine) are available on the NHS

Dementia therapies and lifestyle changes that can help include cognitive stimulation therapy, exercise and diet.

Emerging and experimental dementia treatments include anti-tau treatments, immunotherapy to clear toxic proteins, gene therapy and stem cells to repair or replace damaged neurons and digital and VR therapies.  

Can you reduce dementia-related risks?

While dementia cannot be cured, there are ways to reduce complications and support wellbeing with:

• Regular monitoring for infections.
• Safe home adaptations to reduce falls.
• Assistance with eating and drinking.
• Social interaction and stimulation.
• Professional dementia care support.

Even small changes can significantly improve comfort and safety.

If you’re caring for someone at home, professional dementia home care can help with:

• Personal care (washing, dressing, mobility).
• Nutrition, meal preparation and hydration.
• Medication reminders.
• Safety, companionship and reducing anxiety.
• Support for family carers.

Why home care makes a difference

Many families choose home care to help their loved one stay in familiar surroundings for as long as possible.

Dementia-trained carers can provide reassurance, structure and personalised support – all of which help reduce risk and maintain dignity.

To find dementia home care services near you, you can compare home care agencies, read independent reviews and ratings and find dementia specialists on homecare.co.uk.