Elderly people are often affected by two or more chronic diseases, more frequently cardiovascular diseases, chronic respiratory diseases, metabolic syndrome and cancer. Thesemost frequent chronic diseases share largely preventable risk factors, the most important being smoking and obesity, and may be linked to chronic systemic inflammation. Coexistingchronic diseases affect the course of the primary disease and alter the efficacyand safety of its management. Current clinical practice is dominated by the "singledisease"approach, which has major limitations, and there is increasing evidence that a patient-oriented approach that takes into account the several co-existing components of chronic disease is required. This "change of concept" implies the need for medical specialists to extend their expertise to broader diagnostic and treatment approaches that are traditionally the purview of internal medicine. This new approach also requires a differentapproach to clinical research and teaching, followed by extensive rewriting of medical textbooks and remodelling of teaching curricula to reflect the complexity of the patient affected by chronic diseases.