The Final Stages of Dementia: How Does Dementia Cause Death?

Many people live years or even decades with dementia, which causes death. Researching the symptoms and causes can dramatically help dementia care and prevention.

By Tree Meinch
Feb 27, 2023 4:00 PMAug 8, 2023 5:31 PM
Dementia patient showing cognitive decline
(Credit: FG Trade/GettyImages)


Sign up for our email newsletter for the latest science news

Signs of dementia can spark anxiety and fear in anyone who is aging and experiencing cognitive decline. These concerns often ripple into the psyche of family members, friends and loved ones, too.

Part of the challenge is the many unknowns and uncertainties that accompany dementia, which is not a sole diagnosable disease. Rather, this syndrome — involving a gradual decline in thinking, memory or other cognitive abilities — typically stems from various terminal neurodegenerative diseases.

The most common culprit, Alzheimer’s disease, is now linked to dementia in roughly 1 in 9 Americans age 65 and older, according to a 2022 report from the Alzheimer’s Association. More broadly, at least 55 million people worldwide are living with some form of dementia, per World Health Organization stats.

Many often wonder if there is a cure for dementia, how it causes death and what the options are for dementia care and prevention.

Is There a Cure for Dementia?

Though there is no cure for dementia, most people live for many years or even multiple decades as the syndrome progresses gradually on a case-by-case basis. It typically involves three stages — early, middle and late — before death, either caused by the root neurodegenerative disease or related complications.

Today, researchers are still unraveling the core causes, which is not only advancing care and support but also helping patients and families know what to expect in the process of dementia.

Read More: The 4 Main Types of Dementia

How Does Dementia Cause Death?

The common theme in neurodegenerative cases — including Alzheimer’s, frontotemporal dementia or Lewy body dementia — is that these diseases originate in a particular region of the brain. They kill cells, then slowly spread to neighboring regions.

Alzheimer’s, for example, starts in the hippocampus, commonly associated with memory. More specifically, it destroys neurons and their connections in the entorhinal cortex subregion of the hippocampus. With time, that damaging activity expands to more memory stores nearby and the frontal cortex, where it starts affecting personality and decision-making. 

Read More: How Does Alzheimer's Disease Lead to Death?

The Final Stages of Dementia

In the final stages of dementia, the neurodegenerative disease dives into the deepest parts of the brain. This can inhibit basic bodily functions, such as heart rate and breathing.

Historically, associated complication like respiratory or urinary tract infections and falls have been the cause of death as dementia progresses. But improvements in care for patients are creating more incidents where the death of brain cells is essentially fatal, according to Scott Small, director of the Alzheimer’s Disease Research Center at Columbia University.

“What matters most is the dying of cells,” Small says. 

Read More: How to Treat Dementia No Matter What Age You Are

What are the Signs of Dementia?

Because the outward symptoms and signs of dementia occur relatively late in this process, much research and treatment today focuses on identifying biomarkers in blood that might signal problems during early stages. 

“By the time I see a patient with Alzheimer’s dementia, I’m usually quite certain they’ve had a slowly percolating disorder of at least a decade or longer,” Small says.

But even with blood analyses and dynamic tests, finding the exact indicators of neurodegenerative diseases like Alzheimer’s poses challenges. That’s because these are complex disorders, rather than those that involve a particular defective gene.

“It’s not a simple genetic answer,” Small says of the nature of Alzheimer’s and similar diseases. “A combination of many — technically hundreds — of genes, each having a small weight, [are] conspiring together with the environment to ultimately tip the balance of health.” 

On top of that, even the early outward signs of dementia, such as forgetfulness, can be mistaken for cognitive aging, which is a normal part of getting older. The difference with dementia is the rate of its progression and the severity of its effects.

Read More: How to Diagnose Dementia

Dementia Care and Prevention

Current research suggests that people age 65 and older survive an average of four to eight years after a diagnosis of Alzheimer’s dementia, with some people living as long as 20 years, according to the Alzheimer’s Association.

The good news for those living with dementia today is the growing lineup of treatment options. Dementia care and prevention can include both therapeutic and medicinal options to manage symptoms, and as of the last couple years, multiple drugs designed to treat Alzheimer’s itself.

As of January this year, the U.S. Food and Drug Administration (FDA) approved Leqembi as the second drug of its kind to target the underlying disease process of Alzheimer’s. The first drug of this type, Aduhelm, was approved in the summer of 2021.

Understanding the signs and symptoms to look for and being familiar with the different types of dementia can help medical professionals provide best options for care and prevention.

Read More: How to Talk to Someone With Dementia

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Our List

Sign up for our weekly science updates.

To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2024 Kalmbach Media Co.