Chronic and persistent readings at or above which value define hypertension?

1. Hypertension is chronically elevated blood pressure, not a single high reading. 2. It is defined by chronic and persistent measurements of 140/90 mm Hg or above. 3. Readings between 120/80 and 140/90 mm Hg fall in the prehypertension band instead. 4. Because it is usually silent, patients may not act on it, and heart attack or stroke can follow. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 20 "The Cardiovascular System: Blood Vessels and Circulation", section 20.4 Homeostatic Regulation of the Vascular System_