Is it the blood pressure or the blood vessel?

The physiologic link between vascular health and arterial pressure makes it difficult to separate the adverse effects of pressure and vascular functional and structural alterations in determining the adverse complications of hypertension. Since endothelial dysfunction and nitric oxide deficiency are characteristic features of hypertension and of other risk factors for morbid events, it is proposed that blood pressure elevation may be viewed in part as a complication of functional and structural changes in the microcirculation, and that structural changes in the conduit arteries leading to morbid events may be viewed as a complication of both pressure elevation and endothelial dysfunction. Improvement in endothelial dysfunction will relax the microcirculation and lower blood pressure. Thus pressure elevation and its lowering in resposne to treatment serves as a useful guide to the vascular abnormality and its amelioration, but vascular structural abnormalities are the proximate cause of vascular events and therapy aimed at the vasculature rather than the pressure may serve as a more sensitive and specific guide to treatment.