Aging represents a growing challenge for modern human populations. People are living longer, but diseases associated with aging place an enormous burden on health systems, carers and wider society. It is critical to elucidate the fundamental biology involved so that we can develop treatments for aging-associated conditions. We must also understand the socioeconomic effects and adapt institutions accordingly. Written and edited by experts in the field, this new volume from Cold Spring Harbor Perspectives in Medicine examines recent progress in our understanding of the biology of aging, strategies that may extend health span, and the societal implications. The contributors examine the underlying molecular mechanisms that lead to aging and consider the process from an evolutionary perspective. They also explore how lifespan may be extended, resistance to aging-associated conditions such as Alzheimer's disease, and how society would benefit from increased healthspan. In addition, the authors discuss funding mechanisms for aging research and the way in which the field should develop as a discipline. This volume is thus an important reference for scientists and clinicians involved in geroscience and geriatric medicine, as well as those interested in the broader policy picture.