ABSTRACT
This chapter looks at patterns of health change as people and populations age, in any given places these are affected by socio-economic and environmental factors that affect people's risks. Many of today's risk factors identified by the WHO raise the chances of people developing chronic conditions and diseases, such as heart disease, diabetes and cancers. Greater longevity is associated with increased risk of chronic physical and psychological health or degenerative mental conditions. The chapter reviews two patterns: lifecourse changes in health risks within countries; and those between countries at different stages of development and between social groups. The WHO cites two main mechanisms. The critical periods model occurs when a certain exposure, acting during a specific period, has lasting or lifelong effects that are not substantially modified by later experiences. Risk transition relates to the changing sources and levels of risk over time, for individuals, groups and places, so it is very relevant to age and lifecourse transitions in health.
