Ankle- Brachial Index (ABI)

What is an ABI?

The ankle-brachial index test (ABI) is an easy and painless way to assess your risk for a condition in which the arteries in your legs and ankles are narrowed. People with artery disease in their legs are at a higher risk of heart attack, stroke and poor circulation. They have up to 3 times increase in the risk of dying from a stroke or heart attack.

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 a narrowing or blockage of the arteries in your legs, leading to circulatory problems, heart disease or stroke.

Who should have an ABI test?

Most people who have a blockage in the arteries in the legs have no symptoms.
You should have this test if you are age 50 or older plus have any of these risk factors:

  • Smoking
  • Diabetes
  • Overweight (a body mass index of 25 or greater)


Possible symptoms of artery disease in the legs include:

  • Tightness or squeezing pain in the calf, foot, thigh, or buttock that occurs during exercise (such as walking up a hill or a flight of stairs, running, or simply walking a few steps). It usually happens after a certain amount of exercise and is relieved by rest
  • Leg pain may occur after only minimal activity or even when at rest when there is severe artery disease
  • Cold and numb feet or toes
  • Sores that are slow to heal
  • High blood pressure
  • High cholesterol

How is it performed?

Having an ABI test is 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. Our nurse will ask you to lie on a bed on your back, and she will measure your blood pressure in both your arms using an inflatable cuff.

She will then measure the blood pressure in your ankles and feet using a blood pressure cuff and a hand-held Doppler device that she will press on your skin. The Doppler device lets our nurse hear your pulse in your ankle arteries. The nurse appointment usually takes about 20 minutes. Our doctor will then tell you your result.

It is important to avoid smoking or drinking coffee on the day of the ABI test.

If your ABI result is not normal

You will be advised by our doctor to have a more detailed ultrasound of your leg arteries and will be given a referral letter to book this at an xray clinic on another day. Once you have had that more detailed artery ultrasound, you will need to make an appointment with your usual doctor to discuss the results and any treatment you require.