Healthy ageing depends on genetic, environmental and behavioural factors, as well as broader environmental and socioeconomic determinants. An individual can control some of these factors (usually known as lifestyle factors) but not others. Social determinants of health, such as income and education, influence the choices that individuals can make, and create life circumstances that limit opportunities for healthy lifestyle, and therefore create health inequalities.

The World Health Organization defines healthy or active ageing as 'the process of developing and maintaining the functional ability that enables well-being in older age'.