What are the diagnostic criteria for hypertension?

Diagnostic Criteria for Hypertension

According to the American College of Cardiology/American Heart Association (ACC/AHA) guidelines, hypertension is diagnosed when blood pressure is consistently ≥130/80 mm Hg. 1

Blood Pressure Classification

• Normal BP: <120/80 mm Hg 1
• Elevated BP: 120-129 mm Hg systolic and <80 mm Hg diastolic 1
• Stage 1 Hypertension: 130-139 mm Hg systolic or 80-89 mm Hg diastolic 1
• Stage 2 Hypertension: ≥140 mm Hg systolic or ≥90 mm Hg diastolic 1

Proper Measurement Technique

Accurate blood pressure measurement is critical for proper diagnosis. The following techniques should be employed:

• BP should be measured at every routine clinical visit 1
• Diagnosis should be based on an average of ≥2 readings obtained on ≥2 separate occasions 1
• Patient should be seated with:
  • No conversation during measurement 1
  • Empty bladder 1
  • Correct cuff size on bare arm 1
  • Arm supported at heart level 1
  • Legs uncrossed 1
  • Back and feet supported 1
• Allow 5 minutes of rest before measurement 1

Out-of-Office Confirmation

• Home blood pressure monitoring (HBPM) or ambulatory blood pressure monitoring (ABPM) should be used to confirm the diagnosis and detect white coat hypertension or masked hypertension 1
• All people with hypertension should be counseled to monitor their blood pressure at home after appropriate education 1
• White coat hypertension: office BP ≥130/80 mm Hg but out-of-office BP <130/80 mm Hg 1
• Masked hypertension: normal office BP but high out-of-office BP 1

Special Considerations

• In patients with diabetes, hypertension is defined using the same threshold of ≥130/80 mm Hg 1
• For elderly patients (≥65 years), the diagnostic criteria remain the same, but treatment targets may be individualized based on frailty and comorbidities 1, 2
• In patients with cardiovascular disease and BP ≥180/110 mm Hg, it is reasonable to diagnose hypertension at a single visit 1

Clinical Implications

• Stage 1 hypertension (130-139/80-89 mm Hg) carries approximately a 2-fold increase in cardiovascular disease risk compared to normal BP 1
• Most measurement errors bias readings upward, potentially leading to over-diagnosis and over-treatment 1
• The reclassification of BP from the previous definition (≥140/90 mm Hg) to the current one (≥130/80 mm Hg) resulted in an estimated 14% increase in hypertension prevalence in the US, but only a 1.9% increase in adults requiring antihypertensive drug therapy 1

Understanding these diagnostic criteria is essential for proper identification and management of hypertension, which affects approximately 116 million adults in the US and more than 1 billion adults worldwide 3.