[Frailty, a perspective along the time.]

The demographic changes experienced throughout the 20th century have not only conditioned a series of modifications in the structure of the populations, but have also been accompanied by a change in the epidemiological profiles of the population, which have had as one of their main consequences the change in the main focus of the organizations responsible for health and of the citizens themselves. The main objective of delaying death has been added to avoid disability, the main factor related to health associated with a poor quality of life. In this endeavor, frailty, a nosological entity with less than 25 years of history, has been acquiring increasing relevance and prominence. Throughout this article, it is reviewed, from a historical perspective, how its conceptual frameworks have been defined and delimited, the problems posed by its detection, which have appeared as primary factors in diagnostic work once frailty is diagnosed, how to manage the entity from a point of view of prevention, individual treatment and adaptation of the organization of the health and social systems and the efforts that different national and supranational organizations are making to address the problem, ending with the description of the challenges care and research that frailty has come to pose.