In most cases, the cause of death in people with dementia is an underlying illness or complications resulting from dementia.
Dementia is a progressive condition that involves severe impairments in cognitive functioning and changes in behavior. Although treatments can help to alleviate the symptoms of dementia, the condition is progressive and eventually leads to death.
This article describes how dementia affects life expectancy, including complications that can increase the risk of death. We also list the signs of late stage dementia, and offer advice for those caring for people in the later stages of the condition.
Dementia lowers a person’s life expectancy. A 2019 study found that the average life expectancy for a person with dementia varied according to the age at which they received the diagnosis.
Those who received their diagnosis before the age of 70 years old went on to live another 6.7 years on average, while those who received their diagnosis after the age of 90 years old went on to live another 2.6 years on average.
For people with dementia, it is not necessarily dementia itself that affects life expectancy. It may instead be the underlying conditions that caused or contributed to dementia. These may
During the later stages of dementia, a person may also develop complications that can increase the risk of death. Examples include:
- a weakened immune system, which increases the risk of serious and potentially life threatening infections
- difficulty swallowing, which can lead to malnourishment, weight loss, and aspiration pneumonia
- becoming bedbound, which may exacerbate underlying health problems
Dementia can cause complications that may lead to death. Some of these complications are below.
- breathing difficulties
- a sharp or stabbing chest pain that worsens when breathing deeply or coughing
- fever and chills
- loss of appetite
A person in the later stages of dementia may develop a weakened immune system, which increases their risk of developing pneumonia.
Dementia may also affect a person’s ability to swallow. As a result, food, drink, or saliva may enter the windpipe, resulting in aspiration pneumonia.
A study from 2015 found that pneumonia-related deaths were more common among people who had dementia compared with those who did not have the condition.
COVID-19 is a disease that develops in response to a person contracting the SARS-CoV-2 virus. According to the United Kingdom’s Alzheimer’s Society, this disease may worsen dementia symptoms in the following ways:
- by causing difficulty breathing, which can impair the delivery of oxygen throughout the body
- by entering the brain and causing further damage to brain cells
- by causing delirium, which may worsen confusion
- by causing long COVID symptoms, such as brain fog, which can worsen existing issues with memory and concentration
A 2021 review notes that in November 2020, the rate of death from COVID-19 among people with dementia in long-term care was up to 72%.
A stroke is an interruption in blood supply to part of the brain. It happens because of a blockage or hemorrhage in one of the brain’s blood vessels. A stroke can be both a cause and a complication of dementia.
According to the
Falls and fractures
In the later stages of dementia, a person may develop severe mobility impairments. This can result in falls and accidents that may lead to fractures.
Severe fractures may require surgery, and this comes with a risk of surgical complications, such as:
During the later stages of dementia, individuals may have difficulty swallowing and eating. This can result in severe malnutrition that eventually leads to death.
According to the Alzheimer’s Society, the symptoms of late stage dementia include:
- difficulty recalling memories of recent events
- worsening difficulties with language production and comprehension
- depression and a lack of enthusiasm, interest, or concern
- aggressive behavior
- feeling scared, threatened, or confused
- delusions and hallucinations
- walking more slowly, or becoming bedbound
- problems with eating and swallowing
The Alzheimer’s Association suggests caregivers may wish to try the following to support individuals with late stage dementia:
- playing their favorite music
- reading their favorite books to them
- looking at old photographs together
- providing their favorite foods
- using their favorite scents
- brushing their hair
- sitting outdoors on nice days
A person with late stage dementia will likely require 24-hour care, and caregivers may not always be able to provide this level of support. In such cases, caregivers may want to consider entering the person into hospice care.
A person with late stage dementia may deteriorate rapidly.
The following may be signs that a person is nearing the end of their life:
- deteriorating at a much more rapid pace than before
- agitation or restlessness
- inability to swallow
- developing a chesty or rattling sound when breathing
- irregular breathing
- cold hands and feet
- loss of consciousness
- sleeping most of the time
- diminished interactions
- diminished responsiveness
Dementia lowers a person’s life expectancy, but most dementia-related deaths are due to the underlying cause or complications resulting from dementia.
Dementia complications that may increase the risk of death include malnourishment, infection, and serious injuries from falls and other accidents.
A person with late stage dementia will most likely require constant care from a hospice or other palliative care provider. Caregivers may also benefit from emotional support in the form of talking therapy or a support group.