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.

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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 include:

During the later stages of dementia, a person may also develop complications that can increase the risk of death. Examples include:

Learn about how dementia progresses over time here.

Dementia can cause complications that may lead to death. Some of these complications are below.


Pneumonia is a bacterial, viral, or fungal infection that causes inflammation of the alveoli (tiny air sacs) within one or both lungs. These alveoli may fill with liquid, causing symptoms such as:

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.

A study from 2022 suggests that pneumonia is the leading cause of death among people with Alzheimer’s disease, which is the most common type of dementia.


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.

Strokes can cause a type of dementia called vascular dementia. This type of dementia occurs as a result of the accumulation of damage from several small or large strokes in different areas of the brain.

Researchers suggest that Alzheimer’s dementia may damage blood vessels in the brain, making them more prone to hemorrhage.

According to the Centers for Disease Control and Prevention (CDC), stroke is the leading cause of death in the United States.

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
  • restlessness
  • walking more slowly, or becoming bedbound
  • problems with eating and swallowing
  • incontinence

The National Institute on Aging (NIA) suggests that a person caring for an individual with late stage dementia can use sensory stimuli to provide comfort. Such stimuli may include touch or exposure to familiar sights and sounds.

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.

The NIA also suggests that a person caring for someone with dementia should seek support for themselves. Caregivers are at increased risk of depression and fatigue and may benefit from talking therapy or a support group.

Learn about caregiver burnout here.

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.