Dementia now Australia’s leading cause of death as cases rise; more than 1 million projected by 2065

Dementia has become the leading cause of death in Australia, with the number of people living with the condition set to exceed one million by 2065, the Australian Institute of Health and Welfare (AIHW) said in an updated report released Friday.

The AIHW’s Dementia in Australia report estimates about 433,000 Australians were living with dementia in 2025 and projects a sharp rise in coming decades as the population ages. The report says dementia is the leading cause of death among Australian women and the second leading cause for men.

Dementia is not a single disease but a group of symptoms that cause progressive decline in brain function, affecting memory, behaviour and the ability to perform everyday activities. Symptoms can be subtle and develop over years, prompting clinicians and advocates to describe the condition as a "silent killer." The report highlights that some risk factors are modifiable and that prevention strategies could substantially reduce future cases.

The AIHW estimated that 43 percent of dementia cases can be attributed to six addressable risk factors: overweight or obesity, physical inactivity, high blood sugar, high blood pressure in midlife, smoking and impaired kidney function. The report also flagged frailty and other health declines that compound dementia’s impact in older age.

Professor Matthew Kiernan, chief executive officer of Neuroscience Research Australia, said individuals should begin minimising risk in their 30s and 40s. "We've got to start intervening late 30s early 40s, start 'training' for dementia," he said, urging a national education campaign to improve public understanding of what dementia entails and to reduce stigma.

Kiernan noted that maintaining social engagement, treating mental health conditions and addressing treatable sensory problems such as hearing loss are important defensive measures. "Australians need to be staying engaged in the community, with work, with family, and activities," he said. "If things interfere with that, your risk increases, for example, with depression. Treating depression has an impact in terms of dementia outcomes. Another one is hearing — let's say you go to a dinner party, if you can't hear what people are saying you begin to become isolated and less involved."

The report and experts emphasised lifestyle and medical measures to reduce risk: maintaining a healthy weight, regular physical activity including resistance training, controlling blood sugar and blood pressure in midlife, quitting smoking, treating depression and managing kidney disease. Nutrition that supports muscle strength in older age, such as adequate protein intake, was cited as one way to reduce frailty linked to poorer outcomes.

Dementia Australia chief executive Professor Tanya Buchanan called for federal funding to support a national conversation on dementia and to promote brain health across the lifespan. "With dementia now the leading cause of death for Australians it is more pressing than ever that the federal government commit to funding a national conversation on dementia to raise awareness and promote brain health at all ages," she said.

Advocates living with dementia also urged action on services and community supports. Lil Mirtl, a dementia advocate, said discussions must begin immediately to ensure adequate services and reduce stigma. "We don't have time to feel uncomfortable or awkward about these conversations about dementia — we need to have them now," she said.

There are signs of therapeutic progress: monoclonal antibody treatments that aim to slow cognitive decline are expected to become available in Australia in the near future, and more therapies are in development. Still, the report and experts said prevention remains the most powerful tool to limit the scale of the condition.

The AIHW report provides updated prevalence projections and an evidence base for policy and public health responses as Australia prepares for a rising number of people living with dementia. The report’s findings add urgency to calls for early risk reduction, community engagement, health system planning and public education.

People seeking information or support can contact the National Dementia Helpline at 1800 100 500.