For many older persons, hospitalization results in functional decline despite cure or repair of the condition for which they were admitted. Hospitalization can result in complications unrelated to the problem that caused admission or to its specific treatment for reasons that are explainable and avoidable. Usual aging is often associated with functional change, such as a decline in muscle strength and aerobic capacity; vasomotor instability; reduced bone density; diminished pulmonary ventilation; altered sensory continence, appetite, and thirst; and a tendency toward urinary incontinence. Hospitalization and bed rest superimpose factors such as enforced immobilization, reduction of plasma volume, accelerated bone loss, increased closing volume, and sensory deprivation. Any of these factors may thrust vulnerable older persons into a state of irreversible functional decline. The factors that contribute to a cascade to dependency are identifiable and can be avoided by modification of the usual acute hospital environment by deemphasizing bed rest, removing the hazard of the high hospital bed with rails, and actively facilitating ambulation and socialization. The relationships among physicians, nurses, and other health professionals must reflect the importance of interdisciplinary care and the implementation of shared objectives.