Everything You Need to Know About an Ankle-Brachial Index (ABI) Test

You just came out of a doctor’s appointment and you’ve been diagnosed with peripheral artery disease (PAD). Your mind is reeling from all the information you just received about your condition. When you’re first diagnosed, it can be extremely overwhelming with all the information circulating around the World Wide Web. What are the next steps? What tests will I need? What will I need to know in the future? That’s where we come in. Going forward, we’d like to provide newly-diagnosed PAD patients with enough information to feel prepared and confident.

First, you will need to get an official ankle-brachial index diagnostic test. What is that you may ask? The ankle-brachial index also known as an ABI test, is a quick, minimally invasive way to check your risk of peripheral artery disease (PAD). The ABI test compares your blood pressure in your legs to the blood pressure in your arms. A lower ankle-brachial index can often indicate that there is a blockage in an artery preventing the proper nutrients to reach the rest of your body. According to the Mayo Clinic’s article on Ankle-Brachial Indexes, a low index number also tells the doctor that your risk of circulatory issues has increased which should be monitored more regularly (Mayo Clinic, 2018). This doesn’t mean your arteries are completely blocked, but there is evidence of narrowing, which needs to be detected and treated in order to avoid any future health conditions. Your legs need open arteries so that blood can flow freely, transporting nutrients and oxygen to your limbs.

So how is an ankle-brachial index test conducted? Funny you should ask! Your individual ABI number is your ankle pressure divided by your arm pressure. A number below .99 shows your doctor that there is decreased arterial blood flow, due to PAD with the disease severity increasing as the number gets lower and lower (D. E. Hokanson Inc., 2018). If you have diabetes (typically type 2), your risk of PAD increases significantly. Recent studies show that one in three diabetics will develop PAD during their lifetime (Centers for Disease Control and Prevention, 2016). If you have diabetes and are worried that you might have PAD, your doctor might conduct a similar diagnostic test called a toe brachial index (TBI). These are conducted when patients have very stiff blood vessels that are non-compressible due to calcification. Usually, a doctor will conduct a TBI if your ABI is over 1.3 (D. E. Hokanson Inc., 2018).

Know your numbers! When the doctor hits you with a bunch of unknown numbers at your test, you have no choice to look bewildered. Here is a short key for what doctors are looking for in your ABI numbers.

According to the article Ankle-Brachial Index: Harvard Health, between 1.00-1.29 is considered to be normal. 0.91-0.99 is borderline, which means it should be monitored. 0.41 – 0.90 is moderate PAD, and 0.00 – 0.40 is considered severe PAD (Harvard Health Publishing, 2008).

Now for the actual test itself. Your doctor will ask you to remove your socks and shoes before performing the test. Once you’re comfortable, the doctor will put the measurement cuffs on one of your upper arm and two on both of your ankles. The cuff will fit snuggly, but not tight. The doctor will let you rest for 15-20 seconds before taking the first brachial pressure. The doctor will now inflate and deflate the cuff, similar to a regular blood pressure test. They will take the numbers down and record what comes up on their monitor. Your doctor will measure the wave forms your pressure makes on the screen. Your doctor will then take your pulse at various intervals, preferably between each reading (inflation, deflation). Finally, this is repeated on the other side of your body (D. E. Hokanson Inc., 2018).

It’s important to note that not all people with PAD exhibit symptoms. Actually, many people even call PAD the “stealth disease”. According to the CDC, between 20-40% either don’t experience any symptoms, or don’t notice them enough to see a doctor (Centers for Disease Control and Prevention, 2016). Many seniors often mistake PAD symptoms such as: leg, thigh, hip, calf, or buttocks cramping/pain as just another part of the aging process, instead of a serious, potentially, life-threatening disease.

Both the ABI and TBI tests are pain-less and take about 15 minutes from start to finish. If you have any questions regarding PAD diagnosis, treatments, or just overall information, please feel free to call (855) 514-6149 or visit our website www.usavascularcenters.com anytime. There are many risk factors associated with the development of PAD. If you are over the age of 50, used to, or currently smoke, have a family history of vascular disease, or have high blood pressure or cholesterol, it may be a good idea to schedule an initial arterial consultation! Schedule today.

Our treatments are covered by Medicare, most major health insurance, and some Medicaid plans.



Centers for Disease Control and Prevention (CDC). (2016, June 16). Division for Heart Disease and Stroke Prevention. Retrieved August 29, 2018, from https://www.cdc.gov/DHDSP/data_statistics/fact_sheets/fs_PAD.htm

  1. E. Hokanson, Inc. (2018). How to Perform an ABI | Hokanson. Retrieved August 27, 2018, from https://hokansonvascular.com/articles/133501

Harvard Health Publishing. (2008, October). Ankle-brachial index – Harvard Health. Retrieved August 26, 2018, from https://www.health.harvard.edu/newsletter_article/ankle-brachial-index

Mayo Clinic. (2018, January 10). Ankle-brachial index. Retrieved August 28, 2018, from https://www.mayoclinic.org/tests-procedures/ankle-brachial-index/about/pac-20392934

WebMD. (n.d.). What Is an Ankle-Brachial Index Test? Retrieved August 28, 2018, from https://www.webmd.com/heart-disease/ankle-brachial-test#1