How do causes of death vary by age?

The 10 most common causes of death in 2022 varied by cause type (multiple, underlying, direct and contributory) and age group (Figure 6.1). 

Figure 6.1: Most common causes of death, by cause type and age group, 2022

Acute conditions, external causes of death, and other factors relating to death (such as psychosocial factors) are the most common multiple, underlying, and direct causes of death for younger Australians (aged 44 and under). Chronic conditions and infections are more common for those aged 45 and over.


  1. Deaths registered in 2022 are based on the preliminary version and are subject to further revision by the Australian Bureau of Statistics.
  2. Each death can involve one or more multiple, direct, or contributory cause. As a result, the total percentage by a cause type can be greater than 100.
  3. See Psychosocial factors contribute to death for a description of circumstances included in psychosocial factor groups.
  4. Other CVD: other cardiovascular disease.

Source: AIHW National Mortality Database; Table S6.1.

External causes, mental and behavioural conditions and psychosocial factors are most commonly involved in deaths at ages 15 to 54 

Suicide, road traffic injuries, poisoning, medical complications (for example, from surgery), and the injuries they cause, were among the 10 causes most often involved in deaths at ages 15 to 54. Notably at all ages to 44, psychosocial factors such as personal history of self-harm were frequently involved in causing death (see Psychosocial factors contribute to death). The involvement of mental and behavioural conditions also featured prominently at ages 15 to 54.

Chronic diseases, including coronary heart disease, diabetes, COPD, chronic kidney disease and dementia were commonly involved in causing deaths in most age groups above 25 years. Hypertension was frequently involved in causing deaths from age 55 years and over.

Suicide, CHD and dementia were the most common underlying causes at different ages

Suicide was the most common underlying cause of death between the ages of 15 and 44. Accidental poisoning was among the 4 most common underlying causes between the ages of 15 and 54. Other external causes also featured in the leading underlying cause of death at different ages: drowning in deaths of those aged under 25; road traffic injuries in those aged up to 44; and falls from age 85 upwards.

Coronary heart disease was the leading underlying cause of death between the ages of 55 and 74, and dementia at ages 75 and over. However, coronary heart disease featured among the 10 leading underlying causes from age 25 and dementia from age 65. Other chronic diseases were prominent in the most common underlying causes: cerebrovascular diseases from age 45, COPD from age 55, and diabetes between the ages of 65 and 94.

Cancers were a common underlying cause at all ages but varied by cancer type. The 10 most common underlying causes included, for example: 

  • brain, in deaths aged 0 to 14 and 25 to 44.
  • colorectal between ages 25 to 84.
  • lung between ages 45 and 84.
  • breast between ages 25 and 74.
  • pancreatic between ages 55 and 84.
  • prostate between ages 75 and 94. 

Injuries a common direct cause in younger people, infections in older people

Up to age 54, injuries featured prominently as leading direct causes of death. This is due to their association with external causes. Asphyxiation, drowning, poisoning (substances and drugs), and spinal cord injuries were common direct causes at these ages.

Direct causes of death are consequences or complications of the underlying cause. With a shift from ages 25 in underlying causes from largely external causes to chronic diseases, there is a corresponding change in direct causes. From age 25, cardiac/respiratory arrest was among the 10 leading direct causes of death. Respiratory failure was a common direct cause from ages 45 to 84, multiple-organ failure from ages 45 to 74, and pneumonitis between ages 55 and 94. 

Lower respiratory infections (such as pneumonia) was a leading direct cause of death at all ages, and was the most common at ages 65 years and over. Sepsis was a leading direct cause at all ages except 15–24.

Mental, behavioural and psychosocial factors were common contributors to deaths under age 55

Mental and behavioural conditions (such as drug use and alcohol use disorders, and depressive and anxiety disorders) and psychosocial factors (such as support systems issues, intimate partner issues and personal history of self-harm) dominated the most common 10 contributory causes in deaths aged less than 55 years. At ages 15 to 54, drug use disorders were the most common contributor to death, followed by alcohol use and depressive disorders. 

Childhood events were the leading contributor to deaths at ages under 15.

Chronic disease and risk factor-related conditions were common contributors to deaths from age 55 

In deaths at ages 55 and over, chronic diseases featured prominently among the most common contributory causes. Diabetes was the most common at ages 55 to 84 years, dementia from ages 85 and upwards. COPD, coronary heart disease and chronic kidney disease were also among the leading contributors to death from age 55.

Hypertension was the second leading contributor to death at ages 55 and over, but also a leading contributor to deaths at ages 45 to 54. Coronary heart disease was among the 10 most common contributors in all ages 55 years and upwards. 

Ill-defined causes increased with age

Ill-defined causes such as cardiac or respiratory arrest were prominent among the leading direct causes. Cardiac or respiratory arrest and respiratory failure are modes of dying and are considered ill-defined in mortality coding (WHO 2016). Ill-defined causes that were common among direct causes in deaths at ages 55 and over were: cardiac or respiratory arrest, multiple-organ failure, (unspecified) heart failure, frailty and senility. The proportion of deaths with a direct cause of cardiac or respiratory arrest increased with age.

Unspecified or undetermined (unknown) causes of death were among the most common underlying causes in deaths at ages under 55. A death may be unspecified or undetermined where:

  • after an investigation by the coroner the event or condition causing the death could not be determined.
  • the intent (accident or intentional) of the event is still under investigation.
  • the death of an infant does not meet criteria to be classified as sudden infant death syndrome (SIDS), and a more specific cause of death could not be determined.
  • the death was from unknown natural causes.