Why Do They Die? What Causes Death in People with Alzheimer's Disease?

Causes of Death in Alzheimer's Disease
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Alzheimer's as One of the Top Causes of Death

The Alzheimer's Association notes that Alzheimer's disease is the sixth leading cause of death in the United States. It also points out that out of the top ten causes of death, it's the only one without an effective treatment or cure.

The Centers for Disease Control and Prevention also highlight Alzheimer's as a significant cause of death, pointing out that between 1999 and 2014, deaths attributed to Alzheimer's rose by 55%.

 

One of the challenges in tracking deaths from Alzheimer's is that Alzheimer's disease is not always identified as the cause of death on a death certificate. Sometimes, the conditions that develop from Alzheimer's are listed instead as primary on the death certificate. In other cases, Alzheimer's may have never been officially diagnosed. These challenges in tracking Alzheimer's deaths are demonstrated in one study that found that deaths from Alzheimer's in people over the age of 75 may be as high as six times the count officially recorded.  

Average life expectancy for people living with Alzheimer's is four to seven years after diagnosis, although some people may live as much as 20 years or more. But, what actually causes death in people with Alzheimer's disease?

How Does Alzheimer's Cause Death?

In late stage Alzheimer's disease, people become extremely confused and disoriented. The behavior of someone with late stage Alzheimer's may become more agitated and restless, while other persons experience withdrawal and apathy.

Sometimes, people with later stage dementia cry and call out. Eventually, they lose the ability to communicate, and they may not respond at all.

Additionally, people in the late stages are unable to care for themselves, becoming bedbound and completely dependent on others for their activities of daily living.

Their ability to be continent of bowel and bladder declines. Their appetite decreases as well, and eventually they lose the ability to swallow, leading to poor nutrition and a high risk of aspiration. Aspiration, where a person's food goes "down the wrong tube" when they swallow it, greatly increases the risk of pneumonia developing because they're not able to fully cough and clear the food out of their esophagus and then it settles into their lungs.  

Under these difficult conditions, it's not hard to imagine how vulnerable people with late-stage dementia become to succumbing to infections, pressure sores and pneumonia. One study found that half of all people with dementia admitted to a hospital for pneumonia or a hip fracture died within six months of leaving the hospital.

Another study that examined autopsy reports of people with dementia found the main causes of death were pneumonia, cardiovascular diseases, pulmonary embolism, cachexia, and dehydration.

Other factors that impact the death rate in Alzheimer's disease include advanced age, increased falls and delirium.

A Word from Verywell

Some important decisions to make prior to a person's decline in later stage Alzheimer's disease are related to advanced medical directives.

These directives include designating a healthcare power of attorney and a financial power of attorney, making end of life decisions such as a decision about resuscitation, and conducting research about palliative care and hospice care for someone with dementia. Although these decisions may be difficult, making them ahead of time can increase your peace of mind and allow you to focus on your loved one at the time of decline, instead of on difficult choices and options.

Source:

Alzheimer's Association. Quick Facts. http://www.alz.org/facts/

Centers for Disease Control and Prevention. US Death Rates from Alzheimer’s Disease Increased 55 Percent from 1999 to 2014. https://www.cdc.gov/media/releases/2017/p0525-alzheimer-deaths.html

Javier, Noel S.C., MD, "Palliative Care for the Nursing Home Resident with Dementia", Medicine and Health Rhode Island 93; 12:379-81, December 2010.

National Institute on Aging. Number of Alzheimer’s deaths found to be underreported. May 22, 2014. https://www.nia.nih.gov/news/number-alzheimers-deaths-found-be-underreported

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