There is increasing interest in the concepts through which lay people identify states of health - in their cultural origins and in their connection with preventive or remedial behaviour. A study of the concepts used by elderly Aberdonians is reported, exploiting two data sources: an intensive study of two social networks, and a random sample survey. Concepts of health as the relative absence of disease are distinguished from health as a dimension of strength, weakness and exhaustion, and from health as functional fitness. In this Scottish material, functional fitness is dependent on freedom from disabling disease and not on strength, but strength is an important concept logically distinct from both disease and functional fitness. The `strength' dimension is poorly represented in scientific research on health indicators; but on the other hand lay concepts tend not to acknowledge pain as a dimension in itself. A comparison with a similar French study suggests that while these three lay dimensions of health are present in both cultures, in France functional fitness is dependent on strength as well as on freedom from disabling disease, and this difference seems to be related to the practice of medical consultation.