The fundamental fault in hypertension is unknown. Calling it a fundamental fault, indeed, tacitly begs the question: Is there one fundamental fault, or are there several that are interlinked or interdependent? A simple yes or no answer cannot be offered. This volume is not designed to survey the up-to-date recent advances in research on hypertension, nor intended to provide provisional an­ swers to the so many unknowns in this topic. It is, in fact, an attempt to articulate questions that are worth asking, given the license of an unhibited, albeit disci­ plined, inquiry. The range of expression varies from dogmatic opinion to a declared speculation. Is the primary abnormality an excessive sodium and reduced potassium intake over generations? Or is it hormonal excess, deficiency, imbalance or altered synthesis of abnormal forms? Does the nervous system playa role of active initiation or only of passive maintenance in the genesis of hypertension? Is the heart only a pump acting in concert with the happenings to the vasculature trying to provide adequate flow in the face of vasconstriction induced by neural or humoral factors, or does it sometimes become the culprit by pumping blood flow in excess of demand and thus initiating hypertrophic changes in blood vessels, or by assuming the role of an endocrine organ and being the source of a hormone with influence on cellular transport of sodium and on vasomotor tone? Is an elusive and mysterious fault in the kidney, the primary basis of all of the above