Stages of Hypertension
Blood pressure should be classified using the 2017 ACC/AHA categories: Normal (<120/<80 mm Hg), Elevated (120-129/<80 mm Hg), Stage 1 Hypertension (130-139/80-89 mm Hg), and Stage 2 Hypertension (≥140/≥90 mm Hg), with classification based on the higher category when systolic and diastolic readings differ. 1
Blood Pressure Classification
The current standard classification system divides blood pressure into four distinct categories 1:
- Normal BP: <120 mm Hg systolic AND <80 mm Hg diastolic 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
Key Diagnostic Requirements
Diagnosis requires an average of ≥2 properly measured readings obtained on ≥2 separate occasions 2. When systolic and diastolic readings fall into different categories, always classify the patient by the higher category 1, 2. Out-of-office BP monitoring (home or ambulatory) should confirm the diagnosis to exclude white coat hypertension 1, 3.
Cardiovascular Risk Gradient
The relationship between BP and cardiovascular disease is continuous and progressive, with risk doubling for every 20 mm Hg systolic or 10 mm Hg diastolic increase. 1 Even at the elevated BP range (120-129/<80 mm Hg), hazard ratios for coronary heart disease and stroke are 1.1-1.5 times higher compared to normal BP 1. At Stage 1 hypertension levels (130-139/80-89 mm Hg), this risk increases to 1.5-2.0 times baseline 1.
Management Strategy by Stage
Normal BP (<120/<80 mm Hg)
- Promote healthy lifestyle behaviors to maintain normal BP 2
- No pharmacological intervention required 2
Elevated BP (120-129/<80 mm Hg)
- Implement lifestyle modifications exclusively 2
- Reassess in 3-6 months 2
- No drug therapy indicated unless compelling indications exist 2
Stage 1 Hypertension (130-139/80-89 mm Hg)
The treatment approach differs based on cardiovascular risk stratification:
- Low-risk patients: Lifestyle modifications alone initially, with drug therapy only if BP remains ≥140/90 mm Hg after 3-6 months 2
- High-risk patients (10-year ASCVD risk ≥10% or established CVD): Start lifestyle modifications PLUS single antihypertensive agent immediately 2
- Reassess in 1-2 months if on medication, or 3-6 months if on lifestyle modifications only 2
Stage 2 Hypertension (≥140/≥90 mm Hg)
Immediately initiate both nonpharmacologic therapy AND antihypertensive medications, typically starting with 2 agents of different classes. 3 This aggressive approach is warranted because the absolute CVD risk reduction from BP lowering is greatest in patients at higher baseline risk 3.
- Start combination therapy with 2 antihypertensive agents of different classes 3
- Reassess within 1 month after initiating treatment 2, 3
- Particularly aggressive management with prompt upward dose titration for BP ≥160/100 mm Hg 3
- Monitor electrolytes and renal function 2-4 weeks after initiating therapy if using renin-angiotensin system inhibitors or diuretics 3
Treatment Targets
The target BP for most patients is <130/80 mm Hg, with a minimum acceptable control of <150/90 mm Hg. 2 For patients ≥65 years, target systolic BP <130 mm Hg with no specific diastolic target 2. A 10 mm Hg reduction in systolic BP decreases CVD events by approximately 20-30% 4.
Important Caveats
Measurement Accuracy
Accurate BP measurement requires: patient seated quietly for ≥5 minutes with back supported, feet flat on floor, arm at heart level, using proper cuff size on bare arm, with no conversation and empty bladder 1, 3. Most measurement errors (cuff too small, over clothing, arm hanging, full bladder, crossed legs) bias readings upward, leading to over-diagnosis and over-treatment 1.
Historical Context
The 2017 ACC/AHA guidelines represent a significant departure from JNC 7 (2003), which defined hypertension as ≥140/90 mm Hg and included a "prehypertension" category (120-139/80-89 mm Hg) 1. The European guidelines (ESH/ESC) continue to use ≥140/90 mm Hg as the hypertension threshold with Grade 1,2, and 3 classifications 1. The ACC/AHA change increased US hypertension prevalence by 14% but only increased those requiring pharmacological therapy by 1.9% 5.