Which arm is more accurate for measuring blood pressure, left or right?
Feb 21, 2025
Source: Cainiu Health
Dr. Tian Hongbo
Introduction
There is no specific technique for determining whether measuring blood pressure on the left or right hand is more accurate. Generally, blood pressure can be measured on either the left or right arm, and neither side is absolutely more accurate. Typically, the blood pressure reading from the arm with the higher value is used. If there is vascular disease in one arm, such as arterial stenosis or arteritis, it may affect the blood pressure measurement on that side.
There is no specific technique for measuring blood pressure on either the left or right hand that is considered the most accurate. Generally, either hand can be used for blood pressure measurement, and neither is absolutely more accurate. Typically, the arm with the higher blood pressure reading is used as the reference. Detailed explanations are as follows:
Naturally, there may be some differences in blood pressure between the left and right arms, primarily due to differences in vascular anatomy. Generally, the right brachial artery originates from a branch of the brachiocephalic artery, while the left brachial artery originates from the left subclavian artery. Differences in the branching angles and paths of the blood vessels from the heart may lead to slight variations in blood pressure readings. Most people have slightly higher blood pressure in the right arm, although in some individuals blood pressure may be higher in the left arm or equal in both arms.
For individuals undergoing blood pressure measurement for the first time, it is recommended to measure blood pressure on both arms simultaneously and then compare the values. The arm with the higher reading should be used as the standard for future measurements. Once the arm with consistently higher blood pressure has been identified, it should be used consistently for subsequent monitoring to ensure comparability and accuracy of measurements. This helps reduce errors caused by inter-arm differences and more accurately reflects changes in blood pressure.
If vascular conditions such as arterial stenosis or arteritis exist in one arm, this may affect the accuracy of blood pressure readings from that arm, causing them to be inconsistent with the actual blood pressure. In such cases, blood pressure should be measured on the arm without vascular abnormalities according to the individual's specific condition.
