Ankle Brachial Index

  • The ankle-brachial index (ABI) test is a quick, noninvasive way to check your risk of peripheral artery disease (PAD). PAD is a condition in which the arteries in your legs or arms are narrowed or blocked. People with PAD are at an increased risk of heart attack, stroke, poor circulation, and leg pain.
  • The ABI test compares your blood pressure measured at your ankle with your blood pressure measured at your arm. A low ABI number can indicate narrowing or blockage of the arteries in your legs, increasing your risk of circulatory problems, and possibly causing heart disease or stroke.

INSTRUCTIONS

  • Generally, you won’t need to follow any special instructions before your appointment to have an ABI test performed. You may want to wear loose, comfortable clothing that allows the technician performing your ABI test to easily place a blood pressure cuff on your ankle and upper arm.

HOW THE TEST IS PERFORMED

  • You lie on your back on a table and a technician measures your blood pressure in both your arms using an inflatable cuff. Then, the technician measures the blood pressure in two arteries in both your ankles using the inflatable cuff and a hand-held Doppler ultrasound device that your doctor will press on your skin.
  • The Doppler device uses sound waves to produce images and lets your doctor hear your pulse in your ankle arteries after the cuff is deflated. The procedure for performing an ABI test may vary slightly based on your doctor’s preference.
  • Having an ABI test is painless and similar to getting your blood pressure taken in a routine visit to your doctor. You may feel some pressure on your arm or ankle when the cuff inflates to read your blood pressure.
  • The ABI test should take only a few minutes, and there are no special precautions you’ll need to take following the test. Your doctor will discuss your test result with you.