Blood Pressure Readings: Leg vs. Arm Comparison
Yes, blood pressure readings are typically higher in the leg compared to the arm, with ankle systolic pressures normally 10-20 mmHg higher than brachial pressures in healthy individuals due to arterial anatomy and hemodynamics.
Standard Blood Pressure Measurement Site
The upper arm is the recommended and validated site for clinical blood pressure measurement according to all major hypertension guidelines 1. The International Society of Hypertension and European Society of Cardiology both specify that:
- Blood pressure should be measured using a validated electronic (oscillometric) upper-arm cuff device 1
- The arm should rest on a table with the mid-arm at heart level, with back supported and legs uncrossed 1
- Proper cuff sizing is critical—the inflatable bladder must cover 75-100% of the arm circumference 1
Why Leg Measurements Differ
While the provided guidelines focus exclusively on arm measurements for hypertension diagnosis and management, physiological principles explain leg-arm differences:
Anatomical and hemodynamic factors cause leg pressures to exceed arm pressures:
- Larger arterial diameter in lower extremities
- Greater distance from the heart increases pulse wave amplification
- Hydrostatic pressure effects when measured in standard positions
Clinical Implications
Arm measurements remain the gold standard for several critical reasons:
- All hypertension diagnostic thresholds (≥140/90 mmHg) are based exclusively on brachial artery measurements 1
- Treatment targets and cardiovascular risk stratification derive from arm-based blood pressure data 1
- Validated devices and normative data exist only for upper-arm measurements 1
Important Measurement Caveats
Arm position dramatically affects readings—even within arm measurements, improper positioning causes significant errors:
- Arm resting on lap increases readings by 3.9/4.0 mmHg (systolic/diastolic) 2
- Unsupported arm at the side increases readings by 6.5/4.4 mmHg 2
- These positional errors can lead to misdiagnosis of hypertension 2
Between-arm differences also matter clinically:
- Measure both arms at the initial visit 1, 3
- A systolic difference >10 mmHg indicates increased cardiovascular risk and possible arterial stenosis 1, 3
- Always use the arm with higher readings for subsequent measurements 1, 3
Bottom Line for Clinical Practice
Never use leg measurements for hypertension diagnosis or management—they are not interchangeable with arm readings and lack validated diagnostic thresholds. Stick to standardized upper-arm measurements with proper technique to ensure accurate diagnosis and appropriate treatment decisions 1.