24 October 2023

Dementia Stages

19 min read

What is dementia?

Dementia describes a collection of symptoms that are caused by disorders affecting the brain. It is not one specific disease. Dementia affects thinking, behaviour and the ability to perform everyday tasks. Brain function is affected enough to interfere with the person’s normal social or working life.

  • No two people experience dementia in the same way.
  • It is essential to get a medical diagnosis when symptoms first appear.
  • People often lead active and fulfilling lives for many years after their diagnosis.


Early signs of dementia can be subtle and may not be immediately obvious.

Dementia can happen to anybody, but the risk increases with age. It depends on a combination of age, genes, health and lifestyle.

  • Over the age of 65, dementia affects almost one person in 10.
  • Over the age of 85, dementia affects three people in 10.
  • People under the age of 65 can develop dementia (called ‘younger onset dementia’), but it is less common.
  • Dementia can sometimes be hereditary, but this is quite rare.


Dementia is not a normal part of ageing. 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.

Common symptoms include:

  • memory loss
  • changes in planning and problem-solving abilities
  • difficulty completing everyday tasks
  • confusion about time or place
  • trouble understanding what we see (objects, people) and distances, depth and space in our surroundings
  • difficulty with speech, writing or comprehension
  • misplacing things and losing the ability to retrace steps
  • decreased or poor judgement
  • withdrawal from work or social activities
  • changes in mood and personality.


How is dementia diagnosed?

A number of conditions produce symptoms similar to dementia. These can often be treated. They include some vitamin and hormone deficiencies, depression, medication effects, infections and brain tumours.

It is essential to talk to your doctor when symptoms first appear. If you feel comfortable, take a relative or friend with you.

Here is a video on diagnosing dementia from Dementia.org.au

If the symptoms are caused by dementia, an early diagnosis means early access to support, information and, if it is available, medication.

If symptoms are not caused by dementia, early diagnosis will be helpful to treat other conditions.

What causes dementia?

Many different conditions can cause dementia. In most cases, why people develop dementia is unknown.

The most common types of dementia are:


Read more here about different forms of dementia.

(Published The Conversation.com July 22, 2020) https://theconversation.com/the-ten-factors-linked-to-increased-risk-of-alzheimers-disease-143122

Dementia is the result of changes in certain brain regions that cause neurons (nerve cells) and their connections to stop working properly. Researchers have connected changes in the brain to certain forms of dementia and are investigating why these changes happen in some people but not others.

Alzheimer’s accounts for 60-80% of cases. Vascular dementia which occurs because of microscopic bleeding and blood vessel blockage in the brain, is the second most common cause of dementia. Below we explain the ten factors linked to the increased risk of the most common type, Alzheimer’s

There are ten factors linked to the increased risk of Alzheimer’s disease. Whilst there is still no cure, researchers are continuing to develop a better understanding of what increases a person’s risk of developing Alzheimer’s disease. A study of 396 studies has been able to identify ten risk factors that show the likelihood of developing the disease.


A lower education level is associated with an increased risk of Alzheimer’s disease. Previous evidence shows the longer you spend in education, the lower your risk of developing dementia. Research looking at the brains of people from different educational backgrounds also showed that people who were more educated had heavier brains. As you lose one third of your brain weight because of dementia, a heavier brain may make you more resilient.

Cognitive Activity

Evidence shows that keeping our brains active can also fight against dementia. Activities such as word puzzles stimulate your brain and can strengthen connectivity between brain cells. This connectivity is broken down in dementia.

This latest study shows that we need to continue keeping our brains active, even in older age. Other studies agree that challenging our brains does indeed reduce our chances of developing dementia. See our blog on puzzles and games for the elderly.

Hypertension in mid-life

Healthy hearts have long been linked to a healthy brain. Here, the study indicates that high blood pressure (hypertension) in middle age increases Alzheimer’s risk.

Higher incidence of heart disease in those suffering from high blood pressure impacts on the blood and nutrient supply to the brain. Interestingly, this association still exists even for those who have high blood pressure on its own. The bottom line is that reduced blood supply to the brain is linked with Alzheimer’s.

Orthostatic hypotension

The study also highlighted orthostatic hypotension as a risk factor. This is when someone experiences low blood pressure when standing after sitting or lying down.

Because the body is unable to maintain sufficient blood supply to the brain during posture changes, this can have a long-term debilitating influence on brain activity, as a result of lack of oxygen to the brain, which increases risk of dementia.


The study found diabetes was associated with higher incidence of Alzheimer’s. As diabetes makes our body unable to properly regulate insulin, this changes both the way our brain cells communicate and our memory function – both of which are disrupted in Alzheimer’s disease.

Insulin is essential, as it regulates the metabolism of carbohydrates, fats and protein by helping blood glucose absorb into the liver, fat and muscles. Alzheimer’s disease appears to disrupt the brain’s ability to react to insulin.

Body Mass Index

A higher body mass index (BMI) in under 65s is linked to increased risk of dementia. The study suggests a body mass index between 18.5 and 24.9 for those under 65 – a healthy weight, in other words – may lower dementia risk. However, being underweight in middle age and later life can increase dementia risk.

It’s thought that a mixture of genetics, cardiovascular diseases and inflammation all contribute to this association between BMI and dementia.

Head trauma

Past head trauma is a risk factor – and there is clear evidence that head trauma, such as a concussion, can contribute to the development of dementia. This link was first observed in 1928.

However, it’s uncertain whether single or repetitive head trauma is the contributing factor. It’s clear that brain damage from head trauma is similar to that of dementia. This makes people more susceptible to further damage later from dementia.


High levels of the chemical homocysteine are a risk factor. Homocysteine is a naturally occurring amino acid involved in the production of our body’s defense mechanisms, including antioxidants that prevent cellular damage.

Elevated blood levels of homocysteine in people with dementia was first reported in 1998. Studies have since shown that reducing levels of homocysteine may protect against dementia.

Animal studies suggest elevated levels of homocysteine damage brain cells by interfering with their energy production. Consuming more folate and vitamin B12 can lower homocysteine levels – and may reduce dementia risk.


Those living with Alzheimer’s also often suffer from depression, though it’s uncertain if depression causes Alzheimer’s or is just a symptom of the disease. However, a wealth of evidence supports that depression is indeed a risk factor, as this latest study has found. Research has even indicated a link between the number of depressive episodes – especially ten years prior to dementia onset – and higher risk.

Depression increases levels of harmful chemicals in our brain. An imbalance in these chemicals can lead to loss of brain cells. This, coupled with the loss of brain cells in dementia, increases likelihood of Alzheimer’s


Lastly, stress was identified as a risk factor. Long term stress targets our body’s immune cells, which are important in keeping dementia at bay. In particular, the hormone cortisol is shown to contribute to stress and can impact on memory. Aiming to reduce stress and cortisol levels can therefore reduce the chances of developing dementia.

Signs and Symptoms of dementia

Common signs and symptoms can include
  • Short term memory loss - with all types of memory, the most common being short term memory.
  • Trouble communicating - many people living with dementia have trouble finding the right words, which can cause them to become quieter than they were.
  • Confusion - this can range from a bit of cloudiness to a constant state of mental disarray. For example, being unable to match a face with a name.
  • Moodiness - this may be dependent on the other symptoms happening at the time, for example when a person has forgotten where they left their car keys this can often lead to depression and anxiety. They may also become combative.
  • Inability to understand sarcasm - as brain functions become muddled, those living with dementia may become incapable of distinguishing between sarcasm and seriousness and will begin to take everything literally, misunderstanding common expressions and figures of speech.
  •  Inability to perform simple tasks - completing normal daily tasks can become very complicated for a person with dementia. The disease can completely alter the way the mind processes vital information. For example a person living with dementia may forget how to tie their shoes.
  • Repetition - those living with dementia can develop problems with repetition that can range in severity. Tasks such as going to the shops or washing their car can be repeated over and over. Or simple tasks such as tying and untying shoes may happen several times within the hour. This can often be confused with obsessive compulsive disorder.
  • Loss of interest - people living with dementia can experience a loss of interest in life. This is why it is so important to receive counselling or work with a mental care provider to prevent depression and anxiety.



The 7 Stages of dementia

The cognitive decline that accompanies dementia conditions does not happen all at once - the progression of dementia can be divided into seven distinct, identifiable stages.

Learning about the stages of dementia can help with identifying signs and symptoms early on, as well as those living with dementia and caretakers in knowing what to expect in further stages. The earlier dementia is diagnosed, the sooner treatment can start.

Stage 1: No Cognitive Decline

Stage 1 of dementia can also be classified as the normal functioning stage. At this stage of dementia development, a patient generally does not exhibit any significant problems with memory, or any cognitive impairment. Stages 1-3 of dementia progression are generally known as "pre-dementia" stages.

Stage 2: Age Associated Memory Impairment

This stage features occasional lapses of memory most frequently seen in:

  • Forgetting where one has placed an object
  • Forgetting names that were once very familiar


Oftentimes, this mild decline in memory is merely normal age-related cognitive decline, but it can also be one of the earliest signs of degenerative dementia. At this stage, signs are still virtually undetectable through clinical testing. Concern for early onset of dementia should arise with respect to other symptoms.

Stage 3: Mild Cognitive Impairment

Clear cognitive problems begin to manifest in stage 3. A few signs of stage 3 dementia include:

  • Getting lost easily
  • Noticeably poor performance at work
  • Forgetting the names of family members and close friends
  • Difficulty retaining information read in a book or passage
  • Losing or misplacing important objects
  • Difficulty concentrating


Patients often start to experience mild to moderate anxiety as these symptoms increasingly interfere with day to day life. Patients who may be in this stage of dementia are encouraged to have a clinical interview with a clinician for proper diagnosis.

Stage 4: Mild Dementia

At this stage, individuals may start to become socially withdrawn and show changes in personality and mood. Denial of symptoms as a defense mechanism is commonly seen in stage 4. Behaviors to look for include:

  • Decreased knowledge of current and/or recent events
  • Difficulty remembering things about one's personal history
  • Decreased ability to handle finances, arrange travel plans, etc.
  • Disorientation
  • Difficulty recognizing faces and people


In stage 4 dementia, individuals have no trouble recognizing familiar faces or traveling to familiar locations. However, patients in this stage will often avoid challenging situations in order to hide symptoms or prevent stress or anxiety.

Stage 5: Moderate Dementia

Patients in stage 5 need some assistance in order to carry out their daily lives. The main sign for stage 5 dementia is the inability to remember major details such as the name of a close family member or a home address. Patients may become disoriented about the time and place, have trouble making decisions, and forget basic information about themselves, such as a telephone number or address.

While moderate dementia can interfere with basic functioning, patients at this stage do not need assistance with basic functions such as using the bathroom or eating. Patients also still have the ability to remember their own names and generally the names of spouses and children.

Stage 6: Moderately Severe Dementia

When the patient begins to forget the names of their children, spouse, or primary caregivers, they are most likely entering stage 6 of dementia and will need full time care. In the sixth stage, patients are generally unaware of their surroundings, cannot recall recent events, and have skewed memories of their personal past. Caregivers and loved ones should watch for:

  • Delusional behavior
  • Obsessive behavior and symptoms
  • Anxiety, aggression, and agitation
  • Loss of willpower


Patients may begin to wander, have difficulty sleeping, and in some cases will experience hallucinations.

Stage 7: Severe Dementia

Along with the loss of motor skills, patients will progressively lose the ability to speak during the course of stage 7 dementia. In the final stage, the brain seems to lose its connection with the body. Severe dementia frequently entails the loss of all verbal and speech abilities. Loved ones and caregivers will need to help the individual with walking, eating, and using the bathroom.

By identifying the earliest stages of dementia as they occur, you may be able to seek medical treatment quickly and delay the onset of later stages. Though most cases of dementia are progressive, some may be reversible, and sometimes dementia-like conditions may be caused by treatable underlying deficiencies or illnesses. The more aware you are of these stages, the quicker you will be able to react and seek help, either for yourself or for a loved one.

Source: Global Deterioration Scale for Assessment of Primary Degenerative Dementia

For any further information on dementia, please visit Dementia Australia.