About dementia

Find out about the different types of dementia, who can be affected, and statistics about dementia in Australia.

What dementia is

The World Health Organisation defines dementia as a syndrome that leads to a decline in the ability to process thought, beyond what is expected from the usual consequences of ageing.

Dementia can affect a person’s:

  • memory
  • thinking
  • behaviour
  • communication
  • judgement
  • ability to perform daily activities.

Who can be affected

Dementia can affect anyone of any age; however, it is most common among people aged 65 years and older. While ageing increases your risk of dementia, it is not a normal part of ageing.

Younger onset dementia describes any form of dementia affecting a person under the age of 65.

Types of dementia

There are multiple types of dementia, including:

  • Alzheimer’s disease
  • vascular dementia
  • dementia with Lewy bodies
  • frontotemporal dementia
  • alcohol-related dementia
  • younger onset dementia
  • chronic traumatic encephalopathy (CTE).

You can learn more about the different types of dementia on the Dementia Australia website.

Preventing dementia

Different types of dementia have different causes. Some risk factors for dementia can be reduced by looking after your mental and physical health.

Several factors can contribute to the risk of developing dementia, including:

  • age
  • genetics and family history
  • poor diet
  • lack of exercise
  • smoking
  • drinking alcohol
  • social isolation
  • other diseases or causes of damage to the brain.

To lower your risk of developing dementia, you can: 

  • improve or maintain your physical health through diet and exercise
  • limit alcohol consumption and avoid smoking
  • maintain an active social life
  • keep mentally stimulated.

The most preventable form of dementia is vascular dementia. This type of dementia can be prevented by minimising risk factors for stroke.

For more information on dementia risk factors and how to lower your risk of dementia, visit the Dementia Australia website.

To learn more about the wider determinants of health, including risk factors for dementia, see the National Preventive Health Strategy.

Dementia in Australia

The Australian Institute of Health and Welfare estimates that 401,300 Australians are living with dementia. This number is projected to double by 2058.

In 2020, dementia was the second leading cause of death in Australia, and the leading cause of death among Australian women.

In Australia:

  • 1 in 12 people aged 65 and over are living with dementia
  • 2 in 5 people aged 90 and over are living with dementia
  • dementia prevalence rates are 3-5 times higher among Indigenous Australians.

For reports and statistics about dementia in Australia, see the Australian Institute of Health and Welfare.

Date last updated:

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