ABSTRACT Cardiovascular abnormalities are frequently the cause, as well as the effect, of elevated blood pressure. As such, early cardiovascular disease (CVD) may be established before identifiable blood pressure thresholds are crossed. To identify individuals at risk for CVD at an earlier point in the disease process, as well as to avoid labeling persons as hypertensive who are at low risk for CVD, the Hypertension Writing Group proposes incorporating the presence or absence of cardiovascular risk factors, early disease markers, and target organ damage into the definition and classification scheme of hypertension. To describe both the complexity and progressive nature of hypertension, the following definition is proposed: "Hypertension is a progressive cardiovascular syndrome arising from complex and interrelated etiologies. Early markers of the syndrome are often present before blood pressure elevation is observed; therefore, hypertension cannot be classified solely by discrete blood pressure thresholds. Progression is strongly associated with functional and structural cardiac and vascular abnormalities that damage the heart, kidneys, brain, vasculature, and other organs and lead to premature morbidity and death." Classification of hypertension must involve assessing global cardiovascular risk to situate an individual's risk for CVD and events along a continuum. As knowledge of early CVD continues to evolve, the approach to classifying individuals along that continuum can be expected to evolve accordingly. The four categories currently used to classify hypertension are normal, prehypertension, and stages 1 and 2 hypertension. The population identified with prehypertension includes a subgroup with early CVD. We believe it would be preferable to classify all individuals as either normal or hypertensive, based on their cardiovascular evaluation, using the four categories of normal and stages 1, 2, and 3 hypertension.