An ABI is a simple diagnostic test to determine if you have Peripheral Arterial Disease (PAD).[link] While it can help detect the presence of PAD, it will not show exactly which blood vessels are narrowed or blocked.

For the test, you lie on a table, and the blood pressure in both your arms is measured using an inflatable cuff. Then, the blood pressure in the arteries in both your ankles is measured for comparison, using an inflatable cuff and a hand-held Doppler ultrasound device.

You should wear loose-fitting clothes for an Ankle Brachial Index test so it's easier to place the blood pressure cuff on your arms and ankles. The ABI test only takes a few minutes, but you may be asked to rest for 15-30 minutes before testing begins.