Ankle-Brachial Index (ABI) Test: What to Expect

An ankle-brachial index (ABI) test compares blood pressure in your ankles and arms to help diagnose peripheral artery disease (PAD). PAD occurs when narrowed or blocked arteries reduce blood flow to the legs and feet.

This non-invasive test helps your healthcare provider evaluate circulation concerns and determine whether additional testing or treatment is needed.

Who May Need an ABI Test?

Your healthcare provider may recommend an ABI test if you have signs or symptoms of PAD, including:

• Leg pain or cramping during walking or exercise
• Sores on your feet or legs that heal slowly
• Weak pulses in your legs or feet
  

Your provider may also consider testing based on your age and risk factors, such as tobacco use, diabetes, high blood pressure, high cholesterol or chronic kidney disease.

ABI screening may be appropriate for some higher-risk patients without symptoms, but it is not a routine test for everyone. Your provider can determine whether testing is appropriate for you. American College of Cardiology

What Happens During an ABI Test?

You typically lie on your back after resting for several minutes. A healthcare professional measures blood pressure in both arms and both ankles using inflatable cuffs and a handheld Doppler ultrasound device.

The provider uses these readings to calculate an ABI value for each leg. The measurement helps identify reduced circulation; it does not show the exact location of an arterial blockage.

If you have symptoms during activity but a normal or borderline resting result, your provider may recommend an exercise ABI test. Blood pressure measurements are taken before and after treadmill walking to help evaluate for PAD. 2024 ACC/AHA Guideline

How Should You Prepare, and Are There Risks?

AUsually, no special preparation is needed. Wear loose, comfortable clothing so the cuffs can be placed on your upper arms and ankles. Follow any instructions from your testing office.

The test generally causes little discomfort. The cuffs may briefly feel tight or painful as they inflate, but this should stop once the pressure is released. Most people can resume normal activities afterward.

What Do ABI Results Mean?

A low ABI suggests reduced blood flow from narrowed or blocked leg arteries.

A high ABI may mean the arteries are too stiff for the cuff to compress accurately. Your provider may recommend a toe-brachial index (TBI) test or other testing in this situation.

A normal resting ABI does not rule out PAD in every case, especially when symptoms persist. 2024 ACC/AHA Guideline

What Happens After the Test?

Your healthcare provider will interpret the results alongside your symptoms, medical history and examination findings.

If PAD is diagnosed, treatment may include quitting tobacco, a structured exercise program, heart-healthy eating, and medications to manage cardiovascular risk or symptoms. Some patients may need a procedure to improve blood flow. Treatment depends on the condition's severity and the individual’s needs.

PAD is also associated with a higher risk of heart attack and stroke, making appropriate follow-up important. The ABI test does not diagnose those conditions directly.

Talk With Your Provider About Leg Circulation

If you have leg pain while walking, slow-healing foot sores or concerns about circulation, schedule an evaluation. Your healthcare provider can determine whether an ABI test is the right next step.