Circulation Test

An ankle-brachial index (ABI) test is a simple way for your doctor to check how well your blood is flowing. She would use this test to check for peripheral artery disease. This means you have blockages in the arteries of your legs. This slows down your blood flow, and your limbs don’t get as much of the oxygen they need. The test compares the blood pressure at your ankle with the blood pressure at your arm.

When do I need the test?

You might need the ankle-brachial index test for a few reasons:

1. Your chances of PAD are higher than normal. You're more likely to get PAD as you get older. Even if you don't have any symptoms, you may want to get the test if you're 70 or older. You're also more likely to have this kind of low-flow problem if you're 50 or older and you have any of these:
   • A history of smoking
   • Diabetes
   • High blood pressure
   • High cholesterol
2. You have symptoms of PAD. The main thing you may notice is pain in your legs when you walk or climb stairs. They might feel heavy, numb, or weak. You may also have these symptoms:
   • Less hair on your legs than normal
   • One leg feels colder
   • Skin looks pale or kind of blue
   • Sores on your toes, feet, and legs that don't seem to heal
   • Toenails grow more slowly than they once did
   • Trouble getting an erection, often in men with diabetes
3. You already know you have the condition. If you know you have PAD, your doctor might use the test to see how your treatment has worked so far.

What happens

The test lasts 10 to 15 minutes. First, you lie down on a table. Your doctor uses a cuff that wraps around your arm to take your blood pressure. You’ll feel a mild pressure while it inflates, but that doesn’t last long.

Your doctor will use what’s called a Flocheck device. It connects to a speaker and lets the technician hear your blood flow. To use the device, the technician will first put a dab of gel on your arm just below the blood pressure cuff. Then, she’ll place the ultrasound device on the gel. This helps the technician know when to take your blood pressure reading. She will do the same steps on your other arm, then on both ankles.

What do the results mean?

Your doctor uses the blood pressure results to come up with a number called the ankle-brachial index. Here’s what the numbers mean:

• 0.9 or less: You have PAD. The lower the number, the more blockage you have.
• 1.0 - 1.4: You don't have PAD
• Over 1.4: The test isn't helpful to you. This result means you have stiff arteries, and you can't get useful blood pressure numbers with the cuff. Your doctor will turn to a different test.

You may need changes to your lifestyle or to start making medicine. In some rare cases, your doctor may suggest surgery. If you have severe PAD, your doctor may send you to a vascular specialist, a doctor who treats diseases in arteries and veins.