Dementia has overtaken coronary heart disease as the leading cause of illness, injury and death among Australians aged 65 and over.

Last year, the neurological disorder was responsible for nearly 230,000 years of healthy life lost, marking a 61 per cent spike since 2011, according to the Australian Institute of Health and Welfare.

About 401,300 Australians were estimated to be living with dementia in 2022, up four per cent from the previous year.

This figure is expected to more than double to 849,300 over the next three decades.

Dementia is an umbrella term for various diseases affecting memory and other cognitive abilities and behaviour.

The behaviours and psychological symptoms of dementia (BPSD) include agitation, aggression, insomnia and anxiety.

"While the deterioration of memory, language and cognition are hallmarks of dementia, the majority of people with dementia will also experience at least one type of BPSD as their dementia progresses," AIHW spokeswoman Melanie Dunford said.

"BPSD can have a significant impact on people with dementia, carers and family, and has been associated with early admission to residential care, increased hospitalisation, distress for carers and reduced functional ability for the person with dementia."

Younger onset dementia refers to dementia that begins before the age of 65.

There is currently no cure for dementia, however, the federal government has established a range of support programs including the National Dementia Support Program and the National Dementia Helpline.

Lifeline 13 11 14

beyondblue 1300 22 4636

National Dementia Helpline phone number 1800 100 500