The definition of HTN continues to evolve and an international consensus does not exist. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7), published in 2003, defined HTN as a systolic blood pressure (SBP) 140 mm Hg or a diastolic blood pressure (DBP) 90 mm Hg. This definition was not changed in the 2014 Evidence Based Guideline for the Management of High Blood Pressure in Adults.[2] Prehypertension was classified as SBP 120-139 or DBP 80-89.[3] The 2017 American College of Cardiology/American Heart Association (ACC/AHA) defines HTN as an SBP 130 mm Hg, a DBP 80 mm Hg, or both.[4] Prehypertension was removed as a clinical term; however, elevated blood pressure was added and defined as an SBP of 120-129 with a DBP <80 mm Hg. For the purposes of this CPG, the Work Group, based on our review of the literature, defines HTN as an SBP 130 mm Hg, a DBP 90 mm Hg, or both, assuming proper measurement technique. The reason for the evolution over time in the definition of HTN is because the evidence base supporting the benefits of treatment continue to change. While the relationship between systemic arterial pressure and cardiovascular morbidity or mortality appears to be linear above 115/75 mm Hg based on epidemiologic data, the evidence supporting benefit from treatment of elevated blood pressure starts at a higher threshold.[5] Kaplan and Victor suggests the definition of HTN should be the point at which the benefit of treatment of elevated blood pressure outweighs the risks and cost.[6] Treatment of HTN has long been associated with benefit, but this treatment benefit has not been proven for lowering slightly elevated blood pressures to a normal blood pressure of 115/75 mm Hg. 