Physical frailty syndrome: A cacophony of multisystem dysfunction

Aging experts synthesize converging evidence that the aging-related pathophysiology underpinning the clinical presentation of phenotypic frailty is a state of lower functioning due to severe dysregulation of the complex dynamics in our bodies that maintains health and resilience. When severity passes a threshold, the clinical syndrome and its phenotype are diagnosable. This paper summarizes evidence meeting criteria for physical frailty as a product of complex system dysregulation distinct from the cumulative-deficit-based frailty index of multimorbiditys.