The elasticity of a given arterial segment of the aorta and of big elastic arteries is not constant but depends on its distending pressure. As distending pressure increases, there is greater recruitment of inelastic collagen fibers and thereby a reduction in elasticity. It also depends on structural changes in the medial layer of the elastic arteries (mainly aorta and major arterial conduits), and is largely the result of progressive elastic fibre degeneration.Aortic Pulse Wave Velocity (PWV), is the most robust marker of arterial stiffness, however additional useful information can also be provided by the Central Augmentation Index (AIx C), and pulse pressure. The presence of systemic inflammation in cardiovascular disease and in particular in essential hypertension affects arterial stiffness and increases PWV. Some pharmacological and non-pharmacological interventions may improve arterial stiffness and thereby decrease PWV.