Not only are health and aging significant areas of intellectual inquiry, but they are phenomena that pose problems in societies throughout the world. The developed countries confront burgeoning health care costs and rapidly aging populations. These challenges also confront some developing societies, while others face continued problems of high fertility, mortality and morbidity. Contemporary scholars have recognized that these ostensibly biological problems have psychosocial, social structural and demographic bases. While often treated separately, health and aging have become increasingly intertwined. The nature and sources of health and illness vary at different stages of the life course. As reduced mortality and morbidity have generated aging populations, the health problems that attend many industrialized societies have changed. The aging of the populations may also change the way we frame fundamental problems in the society of health. For example, with the aging of populations in developed societies, chronic rather than acute illness has become the norm. This suggests that chronic illness and disability, once constructed as deviance, should be treated as normal phenomena. Integrating health and aging may also enhance the study of the latter. Therefore, the central problem in the sociology of aging is how to maintain the health and effective functioning of people in middle and later life.