Why it's done

The ankle-brachial index test is done to check for PAD — narrowed arteries that reduce blood flow, usually in your legs. Research indicates that PAD affects about 10 percent of people over age 55.

Your doctor might recommend an ankle-brachial index test if you have leg pain while walking or risk factors for PAD, such as:

• History of tobacco use
• Diabetes
• High blood pressure
• High cholesterol
• Restricted blood flow (atherosclerosis) in other parts of your body