Sleep deprivation, or insufficient sleep syndrome, is a serious sleep problem of epidemic proportions. Outlined in this clinical article are the causes, consequences, and management of sleep deprivation and ways of recognizing it. In this update, Dr. Zupancic elaborates on the symptomatology of the condition as well as recent research in the area of pathogenesis and pathophysiology of insufficient sleep. The article also includes information on the adverse effects sleep deprivation has on cardiovascular health and its association with obesity and diabetes. The delirious effects sleep deprivation has on cognitive function are also discussed.