Ankle-Brachial Index |MedStar Health

The ankle-brachial index (ABI) is a simple, non-invasive test to check for peripheral artery disease (PAD). This test compares the blood pressure measured at the ankle with the blood pressure measured at the arm. A low ankle-brachial index number can indicate a blockage or narrowing of the arteries in the leg. Physicians recommend this test for people who have leg pain while walking or have risk factors for PAD, such as smoking and atherosclerosis in other parts of the body

What to expect

There are no special preparations for the ABI test. You should wear loose-fitting clothing, so your arm and leg are easily accessible. You will rest briefly before the test, and you normally will lie on your back on an examination table.


A health professional will measure your blood pressure in both arms and both ankles. The measurements are taken by using an inflatable cuff and a hand-held ultrasound device that contacts the skin. The device produces images and allows the pulse in the ankle arteries to be heard once the cuff is deflated.

A doctor uses a monitor to check the blood pressure in a patient's ankle during a vascular test.