Screening for blocked leg arteries (ABI) and blocked arm arteries (IAD)


The ankle-brachial index (ABI) is the ratio of the blood pressure at the ankle to the blood pressure in the upper arm. Compared to the arm, lower blood pressure in the leg suggests blocked leg arteries due to peripheral artery disease (PAD). In addition the inter-arm difference (IAD) in blood pressure (> 20mmHg) could also suggest blocked arm arteries.