Scope of the problem
Hypertension (HTN) affects more than 20% of the adult and 3% of the pediatric populations. It is a disease process that contributes to the development of cardiovascular and renal diseases. It appears to be a polygenic, multifactorial disorder with several genes interacting with environmental factors. It is defined by a systolic blood pressure (SBP) greater than 140, diastolic blood pressure (DBP) greater than 90, or someone requiring antihypertensive medications for control of sustained elevations of blood pressure (BP).
As a disease process, HTN was born out of epidemiological studies that showed chronic BP elevation decreased life expectancy; that treatment of HTN reduces stroke, coronary artery disease (CAD), and heart failure; and that most hypertensive patients require more than one agent to achieve BP control.
HTN is an asymptomatic disease process. The exception is a hypertensive emergency. Hypertensive emergencies and urgencies, also known as hypertensive crises, can cause end-organ dysfunction and require controlled management. These hypertensive crises can be viewed as a continuum of the disease process in some patients.
A hypertensive emergency, also known as malignant HTN, is defined as an acute elevation in BP (DBP >130 mmHg in general) with end-organ dysfunction or damage. It requires prompt parenteral treatment with a goal of 25% reduction in mean arterial pressure (MAP) within 30–60 minutes.
A hypertensive urgency is defined as moderately severe to severe HTN with DBP 120–140 mmHg without presenting signs or symptoms of malignant HTN or a concomitant emergency medical condition.