Use the Arm with the Higher Blood Pressure Reading
When blood pressure differs between arms by more than 10 mmHg systolic, you should use the arm with the higher reading for all subsequent measurements and clinical decisions. 1
Initial Assessment
At the first visit, measure blood pressure in both arms to detect inter-arm differences 1, 2. The 2024 ESC Guidelines provide a Class I, Level B recommendation for this practice, emphasizing that a between-arm systolic BP difference >10 mmHg is associated with increased cardiovascular disease risk and may indicate arterial stenosis 1.
Measurement Technique
- Perform sequential arm measurements (simultaneous devices exist but sequential is sufficiently reliable) 1
- Take three measurements in the first arm with 1-2 minute intervals
- Then measure the contralateral arm once
- If a difference is detected, remeasure the original arm to confirm consistency 1
The 10 mmHg Threshold
If systolic BP differs by >10 mmHg between arms, all subsequent measurements must use the arm with the higher BP value 1. This is a Class I, Level B recommendation from the 2024 ESC Guidelines and is echoed by the 2017 ACC/AHA Guidelines 2.
Clinical Rationale
The higher reading arm should be used because:
- It provides a more accurate assessment of true cardiovascular risk 1
- Inter-arm differences >10 mmHg systolic are associated with increased CVD risk and may indicate peripheral arterial stenosis or aortic coarctation 1
- Using the lower reading could lead to underdiagnosis and undertreatment of hypertension 3, 4
Important Caveats
The White Coat Effect
Research suggests that sequential measurements may overestimate inter-arm differences due to the white coat effect—blood pressure naturally decreases with repeated measurements 5. When a large inter-arm difference is detected with sequential measurement, consider remeasuring the original arm to account for this phenomenon 5.
Prevalence of Differences
Inter-arm differences are common in clinical practice:
- 14% of elderly patients have ≥10 mmHg systolic differences 4
- 40% may have ≥10 mmHg diastolic differences 6
- These differences occur equally in both directions (right higher vs. left higher) 4
Sequential vs. Simultaneous Measurement
While guidelines accept sequential measurements as sufficiently reliable 1, recent research from 2026 suggests that sequential measurements may systematically favor the right arm and potentially overestimate inter-arm differences 7. However, simultaneous measurement devices are often not available in routine practice, making sequential measurement the pragmatic standard.
Clinical Pitfalls to Avoid
Do not alternate arms for follow-up measurements—once you identify the higher-reading arm, use it consistently for diagnosis and monitoring 1, 2.
**Do not ignore inter-arm differences <10 mmHg**—while the threshold for changing practice is >10 mmHg, any consistent difference should be noted as it may have clinical significance at the individual level 3.
Do not assume arm dominance explains the difference—research shows no consistent pattern favoring the dominant arm, and differences may reflect underlying vascular pathology 8, 5.