The Stages Of Dementia: Life Expectancy And Symptoms

Medically reviewed by Paige Henry
Updated February 20, 2024by BetterHelp Editorial Team

In general, dementia can be broken down into seven stages, beginning with no cognitive decline and leading up to very severe cognitive decline, also known as late dementia. After a dementia diagnosis, life expectancy typically ranges from eight to 10 years, although it can vary greatly. Treatments are often available to manage symptoms, although there is currently no cure for dementia. Regular exercise, a healthy diet, and keeping your brain busy may be helpful in preventing the development of dementia. If you or a loved one has recently received a dementia diagnosis, you may be experiencing many challenging emotions. A licensed therapist may help you work through them and learn effective coping skills.

Are you or a loved one showing signs of cognitive decline?

What is dementia?

Dementia can be defined as a cognitive symptom characterized by memory loss and impairment of other mental functions. There can be many types of dementia, including vascular dementia, Lewy body dementia, and frontotemporal dementia, caused by various illnesses, such as Alzheimer’s disease and Parkinson’s disease.

Dementia diagnosis

In general, there is no one single way to diagnose dementia. Most people first experience mild symptoms of the condition and then undergo diagnostic tests to identify the cause of their symptoms. If someone starts experiencing symptoms of dementia, their doctor will normally conduct physical and neurological tests in order to determine whether dementia is at play.

Some common dementia diagnosis tests can include questionnaires to measure cognitive functioning and other mental exams. It can be important to remember that memory problems and cognitive difficulties do not always signify dementia. Discuss any changes to your physical or mental health with your doctor to best manage any health conditions that may arise.

Stages of dementia

Like many diseases, dementia can be unique to each individual. However, most types of dementia share similarities regarding their progression. Dementia can normally be broken down into seven stages, also known as the Reisberg Scale. This scale breaks down the stages of the condition based on the amount of cognitive decline one experiences.

Stage 1: No cognitive decline

The first stage of dementia can be seen as having no dementia at all. Someone who has no memory difficulties and is otherwise mentally healthy generally has no dementia and is in Stage 1. Most people in the general population tend to fall into this category.

Stage 2: Very mild cognitive decline

Before anyone enters the early stages of dementia, they are likely to experience a very mild cognitive decline that can be expected with aging. Occasional forgetfulness is not usually a cause for worry and is not necessarily indicative of dementia. The friends and family members of someone with very mild cognitive decline will likely not notice any changes in the person's behavior or mental abilities.

Stage 3: Mild cognitive decline

Mild cognitive decline or mild cognitive impairment (MCI) is a condition that can be common amongst the older population. While not everyone who experiences MCI will develop dementia, it tends to be the first hint of dementia for many people who go on to develop it later in life.

Symptoms of MCI may include problems with memory, as well as broader information processing difficulties, such as difficulty solving a math problem and other challenges with problem-solving capabilities. Unlike people who experience mild forgetfulness or cognitive difficulties as part of aging, the decline of someone with MCI is usually apparent to friends and relatives and may impact the way someone behaves.

Like dementia itself, the cause of MCI is not completely understood. Brain damage that later leads to dementia, such as plaques and tangles, the presence of Lewy bodies, damage from strokes, or shrinkage of certain areas, may all be present in people with MCI, but they’re not usually as severe as those with dementia. MCI can last quite a long time, with an average duration of approximately seven years.

Stage 4: Moderate cognitive decline

Someone with MCI may go on to experience a moderate cognitive decline in which the symptoms of MCI intensify. They may have trouble concentrating or finishing complex tasks, but for the most part, they can live independently and carry out their normal life on a day-to-day basis. However, at this point, the person may begin to withdraw from friends and family because socialization tends to become more difficult. At this stage, physicians may begin to detect signs of dementia.


Stage 5: Moderately severe cognitive decline (mild dementia)

Moderate cognitive decline often progresses into mild dementia. The main difference between the two is usually that mild dementia begins to impact the individual's daily life. Common symptoms of mild dementia can include short-term memory loss, trouble with directions, a tendency to get lost, and, perhaps most notably, personality changes. The person may need assistance with more complex daily tasks, like cooking. The average duration of this stage of dementia is approximately one and a half years.

Stage 6: Severe cognitive decline (middle dementia)

Once someone progresses from mild to moderate dementia, they may no longer be able to carry out their daily tasks independently. Memory deficiencies can become more severe, while basic self-care activities, like bathing or dressing, may require some assistance.

While mild dementia can cause problems with short-term memory, moderate dementia normally includes memory loss of events from the distant past as well as more recent events. Personality and behavior changes can become more pronounced, and those at this stage of dementia tend to feel suspicious or wary of people or situations, even those they are familiar with and who are part of their regular life.

Many people with moderate dementia also have trouble sleeping or experience irregular changes to their sleep patterns, and they may sleep throughout the day while feeling energized or restless at night. This stage of dementia typically lasts approximately two and a half years.

Stage 7: Very severe cognitive decline (late dementia)

Severe dementia normally causes further declining cognitive abilities as well as changes to one's physical abilities. People with severe dementia usually lose their ability to carry out tasks independently and often require full-time assistance. They may eventually lose their ability to communicate, as well as their psychomotor abilities, such as walking and swallowing.

People in this stage of dementia also tend to be more susceptible to dangerous infections like pneumonia. The duration of this final stage of dementia lasts an average of two and a half years.

Dementia life expectancy

Although researchers can determine the average duration of each of the seven stages of dementia, everyone can experience symptoms at different speeds and levels of severity. Someone may experience MCI for decades and never progress into the more severe stages of dementia, while someone else may only experience MCI for a year before their condition worsens.

Although the average life expectancy following a dementia diagnosis is typically eight to 10 years, the time can vary greatly based on the type of dementia, the stage the disease was diagnosed, the individual's general health, and many other factors.

In general, the earlier the condition is detected, the better the prognosis, since the person can start getting help and treatment sooner. Because research for treating dementia is ongoing, early detection may give the individual the opportunity to participate in clinical trials for novel treatment methods that may improve their quality of life and life expectancy.

Treatment options

While there may currently be no way to cure dementia, doctors can prescribe various medications and recommend different types of therapy. It can be vital to consult your doctor before starting, stopping, or changing any type of medication. 

Therapy options may include occupational therapy and talk therapy, among others. Maintaining a structured routine and making changes to a person’s environment to promote safety can also be helpful.

Are you or a loved one showing signs of cognitive decline?

Preventing dementia: What the research shows

If dementia runs in your family and you're worried about how it may affect you, research shows several preventative steps you can take at home in order to significantly reduce the risk of developing dementia.

Exercise regularly

Activities like walking, gardening, and swimming can make all the difference in your health. Exercise can be good for the heart and blood circulation, and it may keep your mind and body healthy.

Keep your brain busy

One of the best ways of keeping dementia at bay can be keeping your mind sharp and active, which may be why puzzles like sudoku, quizzes, learning a new language, and reading to expand your knowledge base are highly recommended.

Cut back on unhealthy habits

If you haven't done so already, try to eliminate or reduce your frequency of smoking and consumption of alcohol and caffeine. You might also eat as healthily as you can. The food you eat can fuel your body and impact your physical and mental health. 

How therapy can support you

A diagnosis of dementia, or even just the emergence of early symptoms of cognitive impairment, can be a significant burden for someone to manage. There can be evidence of comorbidity between dementia and mental health conditions like depression and anxiety.

Dementia can also have an impact on the people in the diagnosed individual's life. Watching a loved one go through the stages of cognitive decline can be challenging, and symptoms of depression or anxiety may occur. This can be especially true among caregivers of people with dementia and Alzheimer's disease. It is not uncommon for them to experience stress and burnout. 

Whether you are struggling with early symptoms of dementia yourself, or you have a loved one going through dementia or another age-related condition, a licensed therapist can help you navigate this difficult period. 

Benefits of online therapy

Online therapy platforms like BetterHelp can be advantageous for those experiencing cognitive decline, in addition to their caregivers, because meeting virtually with a licensed therapist doesn’t usually require anyone to leave their home. Depending on the stage of one’s cognitive decline, changes to routine can prove more disruptive than normal. Meeting from a secure, familiar location may help a patient with dementia feel more comfortable seeking support. 

Effectiveness of online therapy

A 2022 study focusing on online cognitive behavioral therapy for caretakers of people with dementia found that it could decrease distress and help caretakers better manage distressing thoughts. Whether you’re living with dementia or caring for someone who is, online therapy may prove to be a valuable tool.

Below, you may read reviews of BetterHelp counselors from people experiencing similar challenges.

Counselor reviews

"I've been working with Meghan for a few months now, and have never been so confident in a therapist. She is very prompt in her responses, and it is very obvious that she cares about her clients. She has been a source of comfort when my days are bad, and just an ear when my days are not. I don't know what I would do without her. She is truly gifted at her work."

"I've worked with many therapists before, but my work with Don is different. We are focused on my goals and managing the things that I can't change. His approach is incredibly patient and engaging, and I always feel like I have a plan at the end of my sessions. He won't let me slide, but I never feel judged or pushed. I'd highly recommend working with him. He's helped me feel hope during a hopeless time."


Dementia usually consists of seven stages. These typically begin with Stage 1, in which there is no cognitive decline, and end with Stage 7, which is often referred to as late dementia and involves very severe cognitive decline. Once a person has been diagnosed with dementia, their life expectancy may be around eight to 10 years, although this can vary. While there may currently be no cure for dementia, doctors can offer various treatments for symptoms. A dementia diagnosis for yourself or a loved one can be difficult to accept. Working with a therapist online or in person can be helpful.

Navigate the challenges of dementia

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