How do I manually check blood pressure (BP)?

Manual Blood Pressure Measurement Technique

To manually check blood pressure, have the patient sit quietly for 5 minutes with back and arm supported, use a validated device with appropriate cuff size positioned at heart level, take 3 readings 1-2 minutes apart, and average the last 2 measurements. 1

Patient Preparation (Critical First Step)

Before any measurement, proper patient preparation is essential to obtain accurate readings:

• Have the patient sit in a chair with feet flat on the floor and back supported for at least 5 minutes 1
• Ensure the patient has emptied their bladder 1
• Patient must avoid caffeine, exercise, and smoking for at least 30 minutes before measurement 1
• Neither the patient nor observer should talk during the rest period or measurement 1
• Remove all clothing covering the cuff placement location 1

Common pitfall: Measurements taken while sitting on an examining table do not fulfill proper criteria and will yield inaccurate results 1

Equipment and Positioning

Device Selection

• Use a validated blood pressure measurement device that is calibrated periodically 1
• For manual auscultatory measurement, either the stethoscope diaphragm or bell may be used 1

Cuff Size and Placement

• Select correct cuff size so the bladder encircles 75-100% (or 80%) of the arm circumference 1
• Position the middle of the cuff on the upper arm precisely at the level of the right atrium (midpoint of the sternum) 1
• Support the patient's arm (e.g., resting on a desk) at heart level 1

Critical caveat: Using an incorrect cuff size causes systematic errors—a smaller cuff overestimates and a larger cuff underestimates blood pressure 1. Arm position errors are clinically significant, with measurements taken below heart level falsely elevating readings by approximately 9-14 mmHg 2, 3

Measurement Protocol

Initial Assessment

• At the first visit, measure BP in both arms 1
• Use the arm with the higher reading for all subsequent measurements 1
• If readings differ by >10 mmHg between arms, obtain further measurements to confirm the difference is consistent 1

Manual Auscultatory Technique

1. Palpate the radial pulse and estimate the systolic BP by noting when the pulse disappears during cuff inflation 1
2. Inflate the cuff 20-30 mmHg above the estimated systolic pressure 1
3. Deflate the cuff at a rate of 2 mmHg per second while listening for Korotkoff sounds 1
4. Record systolic BP at the onset of the first Korotkoff sound 1
5. Record diastolic BP at the disappearance of all Korotkoff sounds (5th Korotkoff sound) 1
6. Document readings to the nearest even number 1

Number of Readings

• Take 3 measurements with 1-2 minutes between each reading 1
• Average the last 2 readings for the final BP value 1
• If the first reading is <130/85 mmHg, no further measurements are required 1

Important note: The 2024 ESC guidelines recommend averaging the last 2 of 3 readings, while the 2020 ISH guidelines suggest using all readings if elevated 1

Documentation and Follow-up

• Record both systolic and diastolic BP values 1
• Note the time of most recent BP medication taken before measurements 1
• Provide patients with their BP readings both verbally and in writing 1
• Use an average of ≥2 readings obtained on ≥2 separate occasions to diagnose hypertension 1

Special Considerations

Orthostatic Hypotension Assessment

• At the initial visit, assess for orthostatic hypotension by measuring BP at 1 and/or 3 minutes after standing 1
• A drop of ≥20/10 mmHg (systolic/diastolic) defines orthostatic hypotension 1
• This assessment is particularly important in elderly patients, those with diabetes, and treated hypertensives with suggestive symptoms 1

Device Validation

Critical pitfall: Most commercially available devices have never been properly validated, and even validated devices can have errors >5 mmHg in individual patients, particularly in elderly or diabetic populations 4. Lists of validated devices are available at www.stridebp.org 1

Body Position Effects

Be aware that body position significantly affects readings: Supine measurements yield systolic BP approximately 8-10 mmHg higher than seated measurements, while diastolic BP is 5 mmHg higher when seated compared to supine 2, 3, 5. This underscores why standardized positioning is essential for accurate measurement.