There is a paradox in hypertension: whereas the pathophysiological mechanisms of the disease have been related principally to a constriction of small arteries, most of the complications refer to damage of the large arteries, particularly at the site of the brain, the kidney and the heart. In the past, large arteries were poorly investigated in hypertension mainly in terms of change in blood flow. Recent studies clearly show that the large arteries are largely involved in the mechanisms of hypertension not only through changes in mean blood flow, but rather through changes in stiffness of the arterial wall. This aspect may be a key-point for the development of hypertensive complications. Subsequently, the goal of treatment may be not only blood pressure reduction but also improvement of structural and functional abnormalities of the large vessels. These therapeutic aspects are analyzed in detail in the present book.