What are the recommended parameters for blood pressure (BP) monitoring in adults?

Recommended Parameters for Blood Pressure Monitoring

Blood pressure should be based on an average of at least 2 readings obtained on at least 2 separate occasions, and out-of-office measurements (home or ambulatory monitoring) are essential to confirm the diagnosis and guide treatment decisions. 1

Office BP Measurement Technique

Proper measurement technique is fundamental to accurate BP categorization and risk assessment 1:

• Patient preparation: Ensure the patient is seated quietly for at least 5 minutes before measurement, with back supported, feet flat on the floor, and arm supported at heart level 1
• Measurement frequency: Obtain at least 2 readings at each visit, 1 minute apart 1
• Multiple visits: Base clinical decisions on averages from at least 2 separate occasions 1
• Proper equipment: Use validated, calibrated devices with appropriate cuff size 1

Out-of-Office BP Monitoring Parameters

Home Blood Pressure Monitoring (HBPM)

HBPM is recommended to confirm hypertension diagnosis and titrate medications 1:

• Frequency: Take at least 2 readings, 1 minute apart, both in the morning (before medications) and evening (before supper) 1
• Duration: Obtain readings daily, ideally for at least 1 week 1
• Timing for treatment decisions: Begin 2 weeks after treatment changes and during the week before clinic visits 1
• Diagnostic threshold: HBPM readings ≥135/85 mmHg indicate hypertension (lower than office threshold of 140/90 mmHg) 1

Ambulatory Blood Pressure Monitoring (ABPM)

ABPM provides the most accurate cardiovascular risk assessment and should be used to detect white coat and masked hypertension 1:

• Daytime threshold: ≥135/85 mmHg indicates hypertension 1
• Nighttime threshold: ≥120/70 mmHg indicates hypertension 1
• 24-hour threshold: ≥130/80 mmHg indicates hypertension 1

BP Classification Categories

Blood pressure should be categorized using the following thresholds 1:

• Normal: <120/<80 mmHg 1
• Elevated: 120-129/<80 mmHg 1
• Stage 1 Hypertension: 130-139/80-89 mmHg 1
• Stage 2 Hypertension: ≥140/≥90 mmHg 1

When systolic and diastolic readings fall into different categories, classify the patient according to the higher category 1

Screening for White Coat and Masked Hypertension

In Untreated Patients

Screen with ABPM or HBPM when office BP is 130-159/80-99 mmHg to detect white coat hypertension (high office BP but normal out-of-office BP) 1:

• White coat hypertension carries CVD risk similar to normal BP 1
• Masked hypertension (normal office BP but high out-of-office BP) carries CVD risk equivalent to sustained hypertension 1

Screen for masked hypertension with HBPM or ABPM when office BP is 120-129/75-79 mmHg, especially in high-risk patients 1

In Treated Patients

Screen for white coat effect with HBPM when office BP is 5-10 mmHg above goal despite using 3 or more medications 1

Screen for masked uncontrolled hypertension with HBPM when office BP is at goal but target organ damage is present or CVD risk is elevated 1

Monitoring Frequency

Initial Diagnosis Phase

• Adults 18 years and older: Screen at all primary care visits 2
• Confirmation: Obtain out-of-office measurements before initiating treatment 2

Treatment Phase

• Stage 2 hypertension (≥160/≥100 mmHg): Monthly evaluation until control is achieved 3
• Stage 1 hypertension: Follow-up within 3-6 months to assess response 1
• After medication changes: Begin HBPM 2 weeks after adjustment 1

Common Pitfalls to Avoid

Do not rely solely on office BP measurements, as this leads to misclassification in approximately 50% of patients due to white coat effect, masked hypertension, and failure to capture circadian patterns 1:

• White coat hypertension affects 15-30% of patients with elevated office readings 1
• Masked hypertension affects 10-15% of patients with normal office readings 1

Do not delay confirmation with out-of-office monitoring before starting treatment, especially in patients with office BP 130-159/80-99 mmHg 1

Do not use single-visit measurements to diagnose hypertension except in hypertensive emergencies 1

Do not ignore proper measurement technique, as improper positioning, inadequate rest, or incorrect cuff size can falsely elevate readings by 10-30 mmHg 1