Why Should You Monitor Blood Pressure at Home?
Home blood pressure monitoring provides more accurate blood pressure data than office measurements alone, detects white coat and masked hypertension, improves medication adherence, and gives your doctor better information for treatment decisions. A meta-analysis found home monitoring reduces systolic blood pressure by an additional 3.2 mmHg compared to usual care.
The 2020 International Society of Hypertension guidelines and 2017 ACC/AHA hypertension guidelines both strongly recommend home blood pressure monitoring for all patients with hypertension or suspected hypertension. Home measurements better predict cardiovascular outcomes than office measurements because they capture the true blood pressure burden over time, eliminating white coat effects and detecting masked hypertension. A meta-analysis of 37 randomized trials found that self-monitoring with co-interventions (medication titration, lifestyle coaching) reduced systolic blood pressure by 6.1 mmHg at 12 months compared to usual care.
White coat hypertension — where office readings are elevated but home and ambulatory readings are normal — affects 15-30% of patients with elevated office blood pressure. These patients have lower cardiovascular risk than those with sustained hypertension and may not need medication. Conversely, masked hypertension — normal office readings but elevated out-of-office readings — affects 10-15% of adults and carries cardiovascular risk similar to sustained hypertension. Only home or ambulatory monitoring can detect these conditions.
A meta-analysis of 37 trials found self-monitoring with co-interventions reduced systolic blood pressure by 6.1 mmHg
How Do You Take an Accurate Home Blood Pressure Reading?
Sit quietly for 5 minutes with your back supported, feet flat on the floor, and legs uncrossed. Place the cuff on bare skin of your upper arm at heart level. Take two readings 1 minute apart and record both. Avoid caffeine, exercise, and smoking for 30 minutes before measuring. Empty your bladder first.
Proper technique is essential for accurate home readings. The AHA provides detailed guidance: sit in a chair with back support (not on a bed or couch), place feet flat on the floor with legs uncrossed, rest your arm on a flat surface with the cuff at heart level, wrap the cuff snugly on bare skin 1 inch above the elbow crease, and remain still and silent during the measurement. Using the wrong cuff size is one of the most common sources of error — a too-small cuff can overestimate blood pressure by 2-10 mmHg.
Take measurements at consistent times each day, ideally in the morning before medications and in the evening before dinner. Record your readings in a log or use a monitor with memory and app connectivity. Bring your log to every doctor visit. Discard the first day of a new monitoring period as readings tend to be higher due to anxiety about the process. Average the remaining readings over at least 4 days (ideally 7) for the most reliable assessment.
How Do You Interpret Home Blood Pressure Readings?
Home blood pressure targets are typically 5 mmHg lower than office targets. Most guidelines define home hypertension as an average of 135/85 mmHg or higher. Normal home blood pressure is below 130/80 mmHg. Average your readings over at least 4-7 days for the most reliable assessment, excluding the first day.
Home blood pressure classification uses lower thresholds than office measurements to account for the absence of the white coat effect. The European Society of Hypertension defines home hypertension as average systolic ≥135 mmHg and/or diastolic ≥85 mmHg. The treatment target for most home-monitored patients is below 130/80 mmHg. Variability between readings is normal — focus on trends and averages rather than individual readings.
Several patterns should prompt contacting your healthcare provider: consistently elevated readings above 135/85 mmHg despite treatment, any reading above 180/120 mmHg (hypertensive crisis — seek emergency care if symptomatic), a sustained upward trend over weeks, significant discrepancy between morning and evening readings (morning hypertension may indicate suboptimal medication timing), and orthostatic symptoms with low readings suggesting possible overtreatment.
