Blood Pressure Classification Categories
According to the 2017 ACC/AHA guidelines (reaffirmed in 2025), hypertension is classified into four categories: Normal (<120/<80 mmHg), Elevated (120-129/<80 mmHg), Stage 1 Hypertension (130-139/80-89 mmHg), and Stage 2 Hypertension (≥140/≥90 mmHg). 1, 2, 3
The Four BP Categories
The current classification system divides blood pressure into:
- Normal BP: Systolic <120 mmHg AND diastolic <80 mmHg
- Elevated BP: Systolic 120-129 mmHg AND diastolic <80 mmHg
- Stage 1 Hypertension: Systolic 130-139 mmHg OR diastolic 80-89 mmHg
- Stage 2 Hypertension: Systolic ≥140 mmHg OR diastolic ≥90 mmHg
Key Classification Principles
When systolic and diastolic readings fall into different categories, always classify the patient according to the higher category. For example, a BP of 125/92 mmHg would be classified as Stage 1 Hypertension based on the diastolic reading. 1, 2
Base your classification on the average of at least 2 readings obtained on at least 2 separate occasions, not a single measurement. 1
Critical Change from Previous Guidelines
The 2017 ACC/AHA guidelines eliminated the term "prehypertension" and lowered the threshold for Stage 1 Hypertension from 140/90 to 130/80 mmHg. This change was driven by evidence showing that adults with BP in the 130-139/80-89 mmHg range have approximately 2-fold increased CVD risk compared to those with normal BP. 1
Stage 2 Hypertension now encompasses what were previously JNC 7 Stages 1 and 2 (≥140/90 mmHg). 2, 5
Confirmation Requirements
Never diagnose hypertension based solely on office readings. Confirm elevated office BP with out-of-office measurements using either:
- Home blood pressure monitoring (HBPM), or
- Ambulatory blood pressure monitoring (ABPM)
For HBPM/ABPM, the diagnostic thresholds differ slightly from office readings:
- HBPM/daytime ABPM: ≥135/85 mmHg indicates hypertension
- Office BP: ≥130/80 mmHg indicates Stage 1 hypertension
European Guidelines Comparison
The 2024 ESC guidelines use a simpler three-category system:
- Non-elevated BP: <120/<70 mmHg
- Elevated BP: 120-139/70-89 mmHg
- Hypertension: ≥140/≥90 mmHg
Note that ESC maintains the higher 140/90 mmHg threshold for hypertension diagnosis, unlike the ACC/AHA 130/80 mmHg threshold. However, ESC recommends treating elevated BP (120-139/70-89 mmHg) when cardiovascular risk is sufficiently high (≥10% 10-year CVD risk). 6
Common Pitfalls to Avoid
Do not label someone as hypertensive based on a single elevated reading - this leads to overdiagnosis and unnecessary treatment. White coat hypertension (office BP ≥130/80 but out-of-office <130/80 mmHg) affects a substantial proportion of patients and carries CVD risk similar to normal BP, not true hypertension. 1, 4
Do not ignore proper measurement technique. Errors like using an incorrect cuff size, measuring over clothing, unsupported arm, full bladder, or crossed legs all bias readings upward and lead to misclassification. 4
Remember that isolated systolic hypertension (systolic ≥130 or ≥140 mmHg with diastolic <80 mmHg) should be graded using the same systolic thresholds, though very low diastolic pressure (60-70 mmHg) represents additional risk. 7