Learn about the types of dementia, signs and risk factors

What is dementia?

Dementia is an umbrella term for several neurodegenerative disorders affecting an individual’s memory, other cognitive abilities and behaviour, and capacity to carry out normal day-to-day activities.

According to the World Health Organisation (WHO), dementia affects approximately 50 million people globally, though this number is expected to increase rapidly over the next few decades, with approximately 10 million new cases predicted yearly.

It is important to note that dementia does not only impact the person with dementia but also their families, caregivers and communities as a whole.

For more information on dementia, please visit the links below

  1. WHO 2021 Global status report on the public health response to dementia (PDF)
  2. Dementia in Australia 2021: summary report (PDF)
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Dementia is one of the leading causes of care dependency and disability in old age. It also ranks as the seventh leading cause of death. The global societal cost of dementia was estimated to be about USD 1.3 trillion in 2019 and is expected to increase over the next few decades. But there is hope. Knowing your risk factors and making healthy choices to look after your brain and body can help to reduce your dementia risk.

Types of Dementia


Alzheimer’s disease

• Most common type of dementia, forming 60-70% of all cases.

• Main symptom is memory loss which includes episodic memory (for example, trouble remembering specific events such as wedding day or birthday).

• Caused by changes in the brain, including abnormal accumulation of proteins known as amyloid plaques and tau tangles.


Vascular dementia

• Usually mixed with other forms of dementia such as Alzheimer’s disease.

• Includes difficulty with problem-solving, slow thinking and loss of focus.

• Results from issues with blood circulation such as stroke or bleeding into or around the brain.

• Associated with cardiovascular risk factors.


Dementia with Lewy bodies

• Main symptoms are changes in cognition, memory, and movement.

• Symptoms can fluctuate making it difficult to diagnose.

• Visual hallucinations are a common symptom.

• Caused due to presence of abnormal deposits of the protein alpha-synuclein called Lewy bodies.


Frontotemporal dementia

• Main symptoms are changes to behaviour, personality, and language.

• Associated with atrophy in the frontal and temporal lobes of the brain.

• Has an earlier onset than other forms of dementia – after 35 years.

General Signs and Symptoms of Dementia


Dementia is NOT a normal part of ageing.

Due to the many different types of dementia, and the fact that many people experience mixed dementia (that is, not just one specific type of dementia but rather a combination of sub-types), signs and symptoms vary from person to person. Not all changes are a sign of dementia but some common symptoms are listed below.

Impaired Memory

Short- and long-term memory loss (e.g., forgetting recent events or the names of close family members, getting lost in familiar places, often has problems finding words or substituting words inappropriately).

But, some changes may be due to ageing (e.g., occasionally forgetting appointments or a name but remembering later, going into a room and forgetting why they went there but remembering quite quickly, sometimes feels it’s hard to find the right word).

Changes in Behaviour

Potential signs of dementia include aggression, wandering, and withdrawing or losing interest in work, family, or usual interests.

But a change that may be due to ageing could be feeling tired of work, family or social commitments.

Physical Limitations

Someone with dementia might have trouble doing familiar or everyday activities (e.g. getting dressed, brushing teeth). They may also have weakened muscles or poor balance.

For more information on the differences between signs of “typical” ageing or signs of something that may be more serious, please check:

  1. Alzheimer’s Association
  2. Dementia Australia

If you or a loved one has any concerns, please reach out to your healthcare professional for advice best suited to your situation.

Risk Factors

Why is it important to learn about risk factors?

Although ageing is considered to be the strongest predictor of developing cognitive decline and dementia, dementia does not occur simply because we grow older. There is no single factor responsible for causing dementia, rather there are a wide variety of genetic and environmental factors contributing towards susceptibility for developing dementia.

Some risk factors, such as age and family history, are considered to be non-modifiable risk factors. However, there are also many risk factors which are modifiable. Many sub-types of dementia, such as vascular dementia, are associated with health and lifestyle factors such as high blood pressure and smoking, which are modifiable risk factors. If we can better assess these factors, we can work to reduce the likelihood that someone will go on to develop dementia later in life.

By looking at modifiable risk factors and identifying factors making you vulnerable to cognitive decline, it is possible to make changes to your current health and lifestyle in order to delay or reduce your risk for developing cognitive decline and dementia later in life.


High alcohol consumption
Low fish consumption


Atrial fibrillation
High Cholesterol
Insufficient sleep/insomnia


Physical inactivity
Low social engagement
Low cognitive engagement

Discover your personal risk profile