Diagnosing Hypertension
Diagnostic Criteria
- The American Heart Association recommends diagnosing hypertension when office blood pressure is ≥140/90 mmHg on at least 2-3 separate visits 1, 3
- The European Society of Cardiology suggests that if blood pressure is only slightly elevated (140-159/90-99 mmHg), measurements should be obtained over several months 3
- The American College of Cardiology recommends that if blood pressure is markedly elevated (≥160/100 mmHg) or there is evidence of organ damage or high cardiovascular risk, measurements can be obtained over shorter periods (weeks or days) 3
- In severe cases (BP ≥180/110 mmHg with evidence of cardiovascular disease), diagnosis can be made on a single visit 1
Measurement Technique
- The American Society of Hypertension recommends using a validated automated oscillometric upper-arm cuff device for blood pressure measurement 1
- Patients should sit quietly in a chair with feet flat on the floor and back supported for at least 5 minutes before measurement 2
- The patient's arm should be supported at heart level (midpoint of sternum) during measurement 2
- The correct cuff size should be used, with the bladder encircling 75-100% of the arm circumference 1
Out-of-Office Confirmation
- The American Heart Association recommends confirming the diagnosis with home blood pressure monitoring or 24-hour ambulatory blood pressure monitoring whenever possible 1
- Home blood pressure ≥135/85 mmHg confirms hypertension 1, 4
- 24-hour ambulatory blood pressure ≥130/80 mmHg confirms hypertension 1, 4
Special Considerations
- The European Society of Cardiology suggests that standing blood pressure should be measured after 1 minute and again after 3 minutes in certain patient populations, including all treated hypertensive patients at follow-up visits, patients with symptoms suggesting postural hypotension, elderly patients at first visit, and patients with diabetes at first visit 1
- The American College of Cardiology recommends that if blood pressure is ≥160/100 mmHg with evidence of organ damage or very high cardiovascular risk, measurements over days rather than months are appropriate 3