Coronary heart disease remains the most common underlying cause of death in Australia but four in five deaths actually involve more than one cause.
An Australian Institute of Health and Welfare report examined all conditions listed on death certificates in 2022 in order to gain a more complete understanding of the nation's health.
Coronary heart disease is still the biggest killer as it was involved in about 20 per cent of deaths.
Dementia was the second highest as it contributed to 18 per cent, followed by hypertension, cerebrovascular diseases and diabetes.
Almost one quarter of the 191,000 registered deaths had five or more recorded causes.
Understanding what Australians die from is a complex task, according to institute spokesperson Michelle Gourley.
"The answer can vary, depending on how we assess the conditions involved," Ms Gourley said.
"Traditionally, statistics about how people die are based primarily on the initiating or underlying cause of death but death certificates also contain other information that can be useful in understanding why a death occurred."
As an example, she said even though a person's underlying cause of a death may be coronary heart disease, their death certificate may also list other conditions such as a heart attack, diabetes, alcohol use disorders or COVID-19.
"Using different ways of looking at causes of death can enhance our understanding of the roles played by different diseases and conditions in a person's health and in their death," Ms Gourley said.
The most common direct causes of death were lower respiratory infections, cardiac or respiratory arrest and sepsis.
The result varied greatly by age, with suicide, road traffic injuries and accidental poisoning most commonly an underlying cause of death in people aged 15 to 54.
Substance use, depressive disorders and other factors such as self-harm or intimate partner issues were frequently listed as contributing factors for younger people.
Substance use disorders contributed to more male deaths, while dementia and musculoskeletal conditions like osteoporosis contributed to more female deaths.
