Ankle Brachial Index

The Ankle-Brachial Index (ABI) is performed by measuring and comparing blood pressures at the ankles and arms while a patient is at rest. Depending on individual circumstances, the blood pressure measurements might also be repeated after about 5 minutes of walking on a treadmill. An ultrasound blood flow detector, commonly called a Doppler probe, and a blood pressure cuff are used. 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. If there is a drop in the ABI measurement with exercise, this might indicate that Peripheral Artery Disease (PAD) is present.

Why the Test is Performed

Your doctor may order an ABI to screen for Peripheral Artery Disease (PAD). Peripheral artery disease is a condition in which the arteries in your legs or arms are narrowed or blocked. People with peripheral artery disease are at a high risk of heart attack, stroke, poor circulation and leg pain.

Who Needs This Test

Ask your doctor if you should have this test if you are age 50 or older and have any of these risk factors for PAD:

  • Being a current or former smoker
  • Diabetes
  • Overweight (a body mass index of 25 or greater)
  • High blood pressure
  • High cholesterol

Before the Test

There are no special instructions you need to follow prior to this test, however you should wear comfortable clothing which will allow the technician sufficient access to your ankles and upper arms.

After the Test

The ankle-brachial index test will only take a few minutes and there are no special precautions you need to take following the test. If the results are abnormal, further testing may be needed, such as a Lower Extremity Ultrasound or Peripheral Angiography. Your doctor will discuss the results with you during your follow up visit and depending on the severity of your blockage, your doctor may recommend lifestyle changes, medications or surgery to treat PAD.