Dementia rates could nearly double over the next three decades to become the leading cause of death among Australians.

An Australian Institute of Health study commissioned by Dementia Australia predicts by 2054, without a medical breakthrough, dementia rates will surge 94 per cent to affect more than 800,000 people.

Dementia Australia chief executive Maree McCabe hopes the research will inform planning to meet Australia's needs for services and programs.

"It is one of the most significant health and social challenges facing Australia and the world," Ms McCabe said.

More than 420,000 Australians live with varying forms of the condition, which is characterised by deterioration in brain functions including memory, language and problem solving.

Dementia is the second leading cause of death of Australians and the main cause of death for women.

"Provisional data is showing that dementia will likely soon be the leading cause of death of all Australians," Ms McCabe said.

Ten months ago Catherine Daskalakis, 57, was diagnosed with younger onset dementia.

"When I got my diagnosis, the first thing I did was ring the National Dementia Helpline," she said.

"It was the best decision I ever made."

Ms Daskalakis said the figures showed the importance taking advantage of support services.

"I'm close to my family," she said.

"They are always there for me, but I knew I needed more than that.

"It was the start of receiving support which was invaluable."

The research projected all Australian states and territories will experience an increase in dementia rates in the next 30 years.

WA will have the starkest prevalence growth at 109 per cent, followed by the NT at 106 per cent and the ACT at 104 per cent, while Tasmania is expected to have the increase at 52 per cent.

National Dementia Helpline 1800 100 500