Adrenergic neural function is enhanced in hypertension; it not only influences the development and progression of high blood pressure, but also the occurrence of target organ damage, including cardiac hypertrophy, structural and functional vascular changes, and metabolic abnormalities. This paper will review evidence concerning the importance of sympathetic neural mechanisms in the occurrence of the aforementioned alterations. Particular emphasis will be given to the observed interrelationships in essential hypertension between sympathetic function, arterial stiffness, endothelial function, and insulin resistance. Finally, the therapeutic implications of these findings will be discussed...