The 2021 Census looked for the first time at the level of incidence of selected long-term health conditions in the community. The Census question asked respondents if they have been diagnosed with a specific condition (or other condition) from a list of ten conditions plus "other". Combined, these ten conditions comprise approximately 60% of Australia's deaths, and even those which are not deadly contribute substantially to the burden of disease.

Some health conditions, such as arthritis and heart disease increase with age. Other conditions may be suffered at any age. Looking at the long-term health conditions for a specific age group on this page will show whether the specific age group has a greater or lesser prevalence of the condition than the wider population in the City of Casey, and also compare to the prevalence for the age group in a wider geographic area, across the benchmark to the state or Australia level.

As health conditions are also correlated with disadvantage, this topic should be viewed in conjunction with the SEIFA index of disadvantage, and age group comparisons for employment status, unpaid care and household incomes.