From the Guidelines
Hypertension should be diagnosed based on repeated office blood pressure measurements on more than one visit, except when hypertension is severe, and out-of-office blood pressure measurement with ABPM and/or HBPM should be used when logistically and economically feasible. To properly diagnose hypertension, blood pressure should be measured on at least two separate occasions, typically using a calibrated blood pressure device. The patient should be seated comfortably with their back supported, feet flat on the floor, and arm at heart level. Before measurement, the patient should rest for 5 minutes and avoid caffeine, exercise, and smoking for at least 30 minutes. Multiple readings (typically 2-3) should be taken during each visit, with 1-2 minutes between readings, and the patient’s BP is the average of the last two BP readings 1.
Key Considerations for Diagnosis
- Repeated office BP measurements on more than one visit are recommended, except when hypertension is severe (e.g., grade 3 and especially in high-risk patients) 1.
- Out-of-office BP measurement with ABPM and/or HBPM should be used when logistically and economically feasible 1.
- When screening office BP is ≥160/100 mmHg, BP 160–179/100–109 mmHg should be confirmed as soon as possible (e.g., within 1 month) preferably by either home or ambulatory BP measurements, and hypertensive emergency should be excluded when BP ≥180/110 mmHg 1.
- Home blood pressure monitoring is also valuable, with patients taking readings twice daily (morning and evening) for 7 days, discarding the first day's readings and averaging the rest.
- Ambulatory blood pressure monitoring, which measures blood pressure over 24 hours, can be particularly useful for diagnosing white coat hypertension (elevated readings only in clinical settings) or masked hypertension (normal readings in clinical settings but elevated elsewhere).
Importance of Accurate Diagnosis
Proper diagnosis is crucial because hypertension often has no symptoms but significantly increases the risk of heart disease, stroke, kidney disease, and other serious health problems if left untreated. The 2020 international society of hypertension global hypertension practice guidelines also emphasize the importance of using validated BP measuring devices and appropriate cuff sizes for individual patients, and repeated office BP ≥140/90mmHg indicates hypertension, particularly if home BP ≥135/85mmHg or 24h ambulatory BP ≥130/80mmHg 1.
Additional Tests
Once hypertension is diagnosed, additional tests are typically performed to assess for target organ damage and secondary causes, including basic blood tests, urinalysis, and electrocardiogram. These tests help in understanding the extent of the disease and guiding the management plan. The most recent guidelines, such as the 2024 ESC guidelines for the management of elevated blood pressure and hypertension, provide comprehensive recommendations for the diagnosis and management of hypertension, emphasizing the importance of accurate blood pressure measurement and the use of out-of-office blood pressure monitoring when feasible 1.
From the Research
Diagnosis of Hypertension
To diagnose hypertension, multiple blood pressure measurements are necessary, taken on at least two separate occasions 2. The following methods can be used:
- Office blood pressure measurements (OBPM) with at least three distinct measurements
- Home-based blood pressure measurements (HBPM)
- Office-based 30-minute method (OBP30)
- 24-hour ambulatory blood pressure measurements (24 H-ABPM)
Methods for Diagnosing Hypertension
Some key points to consider when diagnosing hypertension:
- OBPM is the most frequently used method, but it is often incomplete or misinterpreted 3
- HBPM and 24 H-ABPM are reliable alternatives to OBPM 4, 5
- Eight to ten blood pressure measurements between 01:00 and 05:00 p.m. are sufficient to give a clinically useful approximation of the daytime mean blood pressure and therefore for diagnosing hypertension accurately 6
- The diagnosis of hypertension should be based on multiple blood pressure measurements, taken on at least two separate occasions, to avoid overestimation of the true prevalence 2
Key Considerations
Some important considerations when diagnosing hypertension: