What is an Ankle Brachial Index (ABI)?

It is a simple test that compares the blood pressure in the arms against the blood pressure of the ankles to determine circulation to the lower limbs. During the test you will be required to lie flat on your back for a minimum of 30 minutes. A Nurse will take the blood pressure in both arms and ankles using an inflatable cuff, similar to the one used in the doctor’s office.


Why might I need an Ankle Brachial Index test?

  • Test for Peripheral Arterial Disease (PAD) where plaque builds up in the arteries of the arms and legs, affecting blood flow. Reduced blood flow can cause pain and numbness to the legs and feet. An ABI test can determine the severity of decreased blood flow but won’t detect exactly which blood vessels have become narrowed or blocked.
  • To determine suitability of compression stockings for patients with lower leg swelling due to venous insufficiency or lymphedema.
  • For patients with lower leg or foot ulcers. An ABI can help determine if there is sufficient blood flow to the affected area to aid in wound healing.
  • If you’ve had surgery to the blood vessels of your legs, your provider might want an ABI to see how well blood is flowing into the leg.


Risk factors for PAD include:

  • Tobacco use
  • Diabetes
  • Hypertension
  • Elevated cholesterol or triglycerides
  • History of Heart Attack, Stroke or TIA
  • Being older than age 70
  • Being younger than age 50 with diabetes and one additional risk factor (listed above)


What are the risks for an Ankle Brachial Index test?

For most people, there are no risks. However, this test is not recommended if you have an untreated blood clot in your leg or untreated cellulitis. Or if you have severe pain in your legs, you may not be able to tolerate the test.


How do I get ready for an Ankle Brachial Index test?

  • Take all your usual medication as prescribed prior to your appointment
  • Avoid smoking within 1 hour of the appointment
  • Wear loose fitting clothing in order to expose your upper arm and lower leg for cuff placement
  • Feet must be clean for proper assessment
  • Avoid strenuous exercise for at least 1 hour prior to your appointment


You should be able to return to your normal activities immediately after the test.  Results will be sent directly to the referring Physician. Be sure to follow up with your provider for the results.