What is the recommended time to take blood pressure?

Recommended Timing for Blood Pressure Measurement

For home blood pressure monitoring, take measurements twice daily—in the morning before breakfast and before taking medications, and in the evening before bed—with 2-3 readings at each time point separated by 1-2 minutes. 1, 2

Morning Measurements (Primary Recommendation)

Morning readings provide the most reliable and clinically significant blood pressure values and should be prioritized. 3

• Take morning measurements after waking but before breakfast and before taking any antihypertensive medications 2
• Morning readings show the smallest measurement error (3.0 mm Hg standard error) and highest reliability compared to other time points 3
• Morning blood pressure is an independent predictor of cardiovascular risk and stroke, as the first 2 hours after waking represent a period of heightened cardiovascular vulnerability 4, 5
• The blood pressure rise occurs after awakening, not before—within the first hour after waking, systolic pressure increases from approximately 107 to 121 mm Hg in normotensives and from 125 to 140 mm Hg in hypertensives 6

Evening Measurements (Complementary)

• Take evening readings before going to bed 1, 2
• Evening measurements are less reliable than morning readings, with greater measurement variability 3
• However, both morning and evening readings are recommended because blood pressure patterns vary considerably between individuals depending on daily routines and medications 1

Proper Measurement Technique

Before taking any reading, patients must: 1, 2

• Avoid tobacco, caffeine, or exercise for 30 minutes prior
• Rest quietly for at least 5 minutes before measurement
• Sit with back straight and supported, feet flat on floor, legs uncrossed
• Position arm at heart level with support on a flat surface
• Remain still and avoid talking during cuff inflation

Recommended Monitoring Schedule

For initial assessment: 1, 2

• Measure blood pressure for 7 consecutive days
• Take 2-3 readings each morning and 2-3 readings each evening
• Discard the first day's measurements (use only days 2-7 for clinical decisions)
• This provides 12-14 total readings for optimal treatment decisions 1

For long-term monitoring: 2

• Conduct measurements for at least 1 week per quarter

Clinical Interpretation

• Home BP ≥135/85 mm Hg indicates hypertension (equivalent to office BP ≥140/90 mm Hg) 2
• Target home BP goal is <135/85 mm Hg, or <130/80 mm Hg for patients with diabetes, coronary heart disease, or chronic kidney disease 2

Important Clinical Caveats

Contraindications to home monitoring: 1

• Patients with atrial fibrillation or frequent ectopic beats—oscillometric monitors may not work reliably in these patients
• Anxious patients who become obsessed with readings—the inherent BP variability may exacerbate anxiety and create a vicious cycle

Device considerations: 1

• Use monitors with memory storage to ensure accurate reporting
• Patients should bring their monitor to the office annually to verify technique and device accuracy
• Avoid "one size fits all" automated cuffs at pharmacies—these are unreliable 1

Timing of Antihypertensive Medications

Current evidence does not support routine bedtime dosing of antihypertensive medications over morning dosing. 7

• All published outcome trials testing bedtime versus morning dosing have major methodological flaws and high risk of bias 7
• The majority of evidence supporting antihypertensive benefits comes from trials using morning dosing 7
• Complete 24-hour BP control should be targeted using long-acting medications administered in a single morning dose 7
• While some studies suggest bedtime dosing may reduce non-dipping patterns in resistant hypertension 8, three ongoing well-designed trials are needed before routine bedtime dosing can be recommended 7