The slow procession of the primary mechanisms of aging leads, at first, to unnoticed changes in the vascular system. Endothelial dysfunction is one of the earliest markers in aging vessels, caused by oxidative stress via the reduction of the availability of NO, on the one hand, and the nitrosylation of proteins, on the other hand. At the same time, glycation of the proteins of the extracellular matrix leads to stiffening of the vessel wall. Together with the loss of elastic fibers, e.g., elastin, this leads to the age-related changes of the vessels. Knowledge of these primary mechanisms of aging may lead to the development of new drugs.