Functional capacity can mean a person’s ability to cope with daily-life activities, but in its widest definition it may mean health status or quality of life.
Functional capacity has often been studied through measuring daily-life activities (ADL scales) or instrumental daily-life activities (IADL scales).
Chronic diseases, depression, cognitive impairment, low physical and social activity and low socio-economic status are also connected to physical functioning.
Even though functional capacity is based on physical health, they are not synonyms; ageing may have different effects on each of them.
Even though diseases increase steadily with the onset of age, the assessments people make of their functioning may actually improve.
Well-being may denote all the domains of human life which make up good living. On a personal level, well-being may mean happiness or satisfaction with life, and on a social level the focus may be on economic welfare. There has been ample research on subjective well-being and the focus has often been on personal feelings of positive and negative effects, happiness, satisfaction with life and self-esteem. It has been suggested that subjective well-being should be defined as a balance between positive and negative affect.