Different Stages of Hypertension
Hypertension is classified into four distinct categories: normal blood pressure, elevated blood pressure, stage 1 hypertension, and stage 2 hypertension, with specific diagnostic thresholds for each category according to the most recent guidelines. 1
Adult Hypertension Classification (Age ≥18 years)
The American College of Cardiology and American Heart Association define blood pressure categories as follows:
| Category | Systolic Blood Pressure | Diastolic Blood Pressure |
|---|---|---|
| Normal | <120 mm Hg | <80 mm Hg |
| Elevated | 120-129 mm Hg | <80 mm Hg |
| Stage 1 Hypertension | 130-139 mm Hg | or 80-89 mm Hg |
| Stage 2 Hypertension | ≥140 mm Hg | or ≥90 mm Hg |
When systolic and diastolic readings fall into different categories, the higher category should be assigned for classification purposes 2, 1.
Pediatric Hypertension Classification (<18 years)
For children and adolescents younger than 18 years, hypertension is defined differently:
- Normal BP: <90th percentile for gender, age, and height
- Prehypertension: ≥90th percentile but <95th percentile, or ≥120/80 mm Hg but <95th percentile
- Stage 1 Hypertension: From 95th percentile to 5 mm Hg above the 99th percentile
- Stage 2 Hypertension: >5 mm Hg above the 99th percentile 2
Pediatric hypertension requires at least three separate measurements at or above these thresholds for diagnosis.
Clinical Significance of Different Stages
Normal BP: Optimal cardiovascular health with minimal risk
Elevated BP/Prehypertension: Associated with increased risk for developing hypertension and cardiovascular disease
Stage 1 Hypertension:
Stage 2 Hypertension:
- Significantly increased risk of cardiovascular events, approximately 2.1 times greater risk for stroke compared to normal BP 3
- Requires both lifestyle modifications and pharmacological intervention
Hypertensive Crisis (Beyond Regular Classification)
Beyond the standard classification, severe elevations in blood pressure may constitute a hypertensive crisis:
- Hypertensive Urgency: Severe hypertension (>180/120 mm Hg) with minimal or no end-organ damage
- Hypertensive Emergency: Severe hypertension with acute end-organ damage requiring immediate intervention 4
European Classification Differences
The European Society of Cardiology and European Society of Hypertension use a different classification system:
- Normal: <140/90 mm Hg
- Grade 1 Hypertension: 140-159/90-99 mm Hg
- Grade 2 Hypertension: 160-179/100-109 mm Hg
- Grade 3 Hypertension: ≥180/≥110 mm Hg 1
Diagnostic Considerations
- Blood pressure should be measured accurately with at least 2 readings on 2 separate occasions
- When systolic and diastolic readings fall into different categories, the higher category should be used for classification
- Out-of-office monitoring (home or ambulatory) is recommended to confirm diagnosis and detect white-coat or masked hypertension 1
Clinical Implications
The progressive nature of hypertension means that cardiovascular risk increases continuously with blood pressure levels. Even BP values in the elevated range (120-129/<80 mm Hg) are associated with increased cardiovascular risk compared to normal BP, with a further significant increase in risk at stage 1 and stage 2 hypertension 2, 1.
Understanding these classifications is crucial for appropriate risk stratification and treatment decisions to reduce morbidity and mortality associated with hypertension.