You can live with dementia for varying lengths, but on average, people live 4 to 8 years after diagnosis, though this can range from a few years to 20 years or more, depending heavily on the type of dementia, age at diagnosis, overall health, and other factors like genetics and lifestyle. Alzheimer's often has a longer prognosis (around 8-10 years), while other types like Vascular Dementia or Dementia with Lewy Bodies might have shorter averages (around 5-6 years).
Signs of late-stage dementia
You and your family may worry about how long you can look after yourself, particularly if you live alone. Everyone experiences dementia differently and the rate at which symptoms become worse varies from person to person. But with the right support when you need it, many people live independently for several years.
No or Little Dementia
Life expectancy with dementia varies greatly but averages a few years to over a decade, often 4 to 8 years for Alzheimer's, depending heavily on age at diagnosis (younger means longer), type (Alzheimer's generally longer than Vascular), and other health conditions, with newer research showing averages like 5.1 years for women and 4.3 for men from diagnosis, but with wide ranges from shorter for older adults to longer for some.
The person with dementia is no longer managing at home as well as they used to. For example, they are no longer able to do daily tasks, like eating, without the support of another person. The person is no longer safe at home. For example, they keep having falls.
Rapidly progressive dementias (RPDs) are dementias that progress quickly, typically over the course of weeks to months, but sometimes up to two to three years. RPDs are rare and often difficult to diagnose. Early and accurate diagnosis is very important because many causes of RPDs can be treated.
“People with dementia benefit from consistent and predictable environments and caregivers. Nursing homes may offer more people to help with medical and social needs, but that might mean sharing a room with someone with different daily habits or distressing behavior symptoms.”
Many people affected by dementia are concerned that they may inherit or pass on dementia. The majority of dementia is not inherited by children and grandchildren. In rarer types of dementia there may be a strong genetic link, but these are only a tiny proportion of overall cases of dementia.
Alzheimer's disease – around eight to 10 years. Life expectancy is less if the person is diagnosed in their 80s or 90s. A few people with Alzheimer's live for longer, sometimes for 15 or even 20 years. Vascular dementia – around five years.
The number one cause of dementia is Alzheimer's disease, responsible for 60-80% of cases, characterized by brain plaques (beta-amyloid protein) and tangles (tau protein) that damage nerve cells, leading to progressive memory and cognitive decline, though vascular dementia from blood vessel damage is also a significant factor.
Research suggests that pain and Alzheimer's disease share some of the same brain pathways. Inflammation in the brain, particularly in the locus coeruleus, may contribute to both conditions. This means that even if a dementia patient doesn't have an obvious injury, they could still be experiencing significant pain.
Playing music, having objects to touch and interact with, and hand massage can all help people with dementia in the later stages.
Even though a person with dementia may end up sleeping more than a typical person of their age – even as much as 14–15 hours a day – it is unlikely to all be good quality sleep. Sleeping a lot can also be influenced by people's sleeping patterns before they had dementia, as some people need more sleep than others.
It's not always a good idea for someone with dementia to be involved in the formal part of the funeral. It can be extremely upsetting and intense if they forget that their loved one has died and then are reminded of it again at the funeral.
Recognizing the Signs of Dementia Progression
Increased Confusion and Disorientation – As dementia progresses, individuals may struggle to recognize familiar faces, places, or even the time of day. They may get lost in once-familiar settings or have difficulty following conversations.
When someone gets the diagnosis of dementia, a cure is only very rarely possible (see p2 About Reversible Dementias). In the current issue of Neurology, Sacks and Shulman1 report one of these rare cases of a reversal of dementia involving a patient on steroid medication.
Never argue, correct, or overwhelm your loved one with dementia; instead, avoid telling them they are wrong, don't bring up upsetting topics like the death of loved ones, and don't treat them like a child or talk down to them, focusing instead on validation and gentle redirection to maintain their dignity and reduce anxiety.
The "2-finger test" for dementia involves an examiner showing a hand gesture (like interlocking index and middle fingers) and asking the patient to copy it, testing motor skills, visual memory, and coordination, as difficulties can signal early cognitive decline, but it's a screening tool, not a definitive diagnosis, prompting further medical evaluation. Other related tests include finger-tapping and finger-to-nose, looking for hesitation or misjudgment in movement.
Smoking, low physical activity, and a poor diet are all lifestyle and environmental influences that have been linked to rapid dementia decline. Physical activity promotes cardiovascular health, which in turn improves brain function. Those who lead a sedentary lifestyle may experience faster cognitive decline.
Life expectancy after a diagnosis of dementia decreases with increasing age. For example, an average person diagnosed with Alzheimer's disease between ages 70-79 can expect to survive seven more years, while a diagnosis after age 90 is associated with an expected survival of only 2.8 additional years.
In general, it is not safe to leave a dementia patient alone for even short periods of time once they enter what is often recognized as the moderate stage of dementia. This is because they may no longer have the judgment or ability to handle any number of emergencies, such as a fire or a fall.
While family caregivers often provide the primary daily support for individuals with dementia, legal responsibility for decision-making and financial management can fall to spouses, adult children (depending on filial responsibility laws), or court-appointed guardians or conservators, especially in the absence of a ...
A big study of people with dementia in the US found that about a quarter were sometimes either aggressive or agitated, and a UK study found about 1 in 5 people with Alzheimer's disease were sometimes aggressive. So it's a common symptom of the condition.