This document discusses postoperative delirium, which is more common in elderly patients. Risk factors include advanced age, comorbidities, cognitive impairment, reduced functional status, and malnutrition. Incidence rates of postoperative delirium range from 3.6% to 53.3%. Preventative measures include fast-track surgery, avoiding unnecessary premedication, adequate pain management, and prompt diagnosis and treatment if delirium occurs.