Chapter 33
Hypertension
Over 100 million Americans have hypertension
Hypertension: The Silent Killer
Hypertension affects approximately 46% of adult Americans and is defined as a systolic blood pressure at or above 130 mmHg or a diastolic blood pressure at or above 80 mmHg (ACC/AHA 2017 guidelines).
Hypertension is the single most important modifiable risk factor for cardiovascular disease, stroke, heart failure, and kidney disease. It earns the label 'silent killer' because most patients have no symptoms until target organ damage has already occurred β often after years or decades. Blood pressure equals cardiac output times systemic vascular resistance (BP = CO x SVR). Antihypertensives reduce BP by targeting one or both. The goal is not simply to lower a number β it is to prevent the consequences: MI, stroke, heart failure, and CKD.
Why the Guidelines Changed in 2017
The ACC/AHA 2017 guidelines lowered the Stage 1 threshold from 140/90 to 130/80 mmHg, instantly making 46% of Americans 'hypertensive.' The rationale: cardiovascular risk begins at 115/75 mmHg and doubles with every 20/10 mmHg rise. Earlier diagnosis allows lifestyle intervention and monitoring before true pharmacological HTN develops. The older JNC-7 (140/90 for Stage 1) is still widely tested on licensing exams β know BOTH classification systems.