Peripheral arterial disease (PAD) screening is a set of simple, noninvasive tests designed to detect narrowed or blocked arteries in the legs before symptoms appear. The most common screening method, the ankle-brachial index (ABI), compares blood pressure readings in your ankles and arms to check whether blood is flowing normally to your lower limbs. The goal is to catch the disease early, since many people with PAD have no symptoms at all but face a significantly higher risk of heart attack, stroke, and amputation.
Why Screen for a Disease You Can’t Feel
PAD narrows the arteries that carry blood to your legs and feet, usually because of the same plaque buildup that causes heart disease. The tricky part is that many people with PAD never experience leg pain or other obvious warning signs. Without screening, these individuals have no idea they’re at elevated risk for serious cardiovascular events. An early diagnosis flags them for closer monitoring, lifestyle changes, and treatment of shared risk factors like high blood pressure, high cholesterol, and high blood sugar.
Screening programs aim to reduce the chances of intermittent claudication (cramping leg pain when walking), critical limb ischemia (severe blood flow restriction that can threaten a limb), cardiovascular events, amputation, and early death. Identifying PAD also signals that atherosclerosis may be present in other arteries, including those supplying the heart and brain.
Who Should Be Screened
Not everyone needs PAD screening. The yield of testing in younger adults without risk factors is low, and routine screening in that group isn’t recommended. Guidelines from the American College of Cardiology and the American Heart Association, updated in 2024, identify four groups at increased risk who benefit most from screening:
- Adults 65 and older, regardless of other risk factors.
- Adults 50 to 64 who have risk factors for atherosclerosis (diabetes, a history of smoking, high cholesterol, high blood pressure), chronic kidney disease, or a family history of PAD.
- Adults under 50 with diabetes plus at least one additional atherosclerosis risk factor.
- Anyone with known atherosclerotic disease in another part of the body, such as coronary artery disease, carotid artery narrowing, or an abdominal aortic aneurysm.
The Society for Vascular Surgery takes a slightly different approach, flagging screening as reasonable for adults over 70, current smokers, people with diabetes, those with an abnormal pulse on physical exam, or those with other established cardiovascular disease. The common thread across all guidelines is that screening targets people whose age, habits, or health history put them at meaningfully higher risk.
How the Ankle-Brachial Index Test Works
The ABI is the primary screening tool. It’s painless, takes about 10 to 15 minutes, and uses equipment you’ve seen in any doctor’s office: blood pressure cuffs and a small handheld ultrasound probe.
You lie flat on your back. A technician wraps a blood pressure cuff around your upper arm and inflates it, then uses the ultrasound probe to listen for blood flow in the artery as the cuff slowly deflates. The pressure reading at the moment blood flow returns is your systolic pressure for that arm. The technician repeats this on the other arm and then on both ankles, placing the cuff just above each ankle and the probe over the artery on top of the foot or behind the inner ankle bone.
Once all four readings are collected, the technician divides the higher ankle pressure by the higher arm pressure. That ratio is your ABI score.
What Your ABI Score Means
A normal ABI falls between 1.0 and 1.4. This means the blood pressure in your ankle is equal to or slightly higher than the pressure in your arm, which is what you’d expect when arteries are clear.
A score of 0.90 to 0.99 is considered borderline. It suggests that your peripheral arteries may be starting to narrow, though blood flow isn’t significantly blocked yet. Your provider may recommend a follow-up test, sometimes an exercise ABI where you walk on a treadmill and then have your pressures measured again to see how your arteries perform under stress.
A score below 0.90 typically indicates PAD. The lower the number, the more significant the blockage. Scores in the 0.40 to 0.70 range point to moderate disease, while anything below 0.40 suggests severe restriction. A score above 1.4 can also be a red flag, but for a different reason: it usually means the arteries are stiff and calcified, which makes the cuff unable to compress them properly. In that case, a different test is needed.
When the ABI Isn’t Enough
Calcified arteries are common in people with diabetes and in older adults with chronic kidney disease. The calcium deposits in the artery walls make them rigid, so the blood pressure cuff can’t squeeze them shut normally. This produces a falsely high ABI reading that looks reassuring even when PAD is present.
In these situations, the toe-brachial index (TBI) offers a more reliable alternative. The arteries in the toes are generally spared from this type of calcification, so measuring blood pressure at the big toe gives a truer picture of blood flow. The test works the same way as an ABI, just with a tiny cuff placed around the toe. Research has found that TBI is the preferred method for evaluating lower limb circulation when artery wall calcification is suspected, and many clinicians will order both an ABI and a TBI together for patients with diabetes to get the most complete assessment.
Insurance and Cost Considerations
Coverage for PAD screening depends on why the test is being ordered. Medicare and most private insurers cover noninvasive vascular studies when three conditions are met: you have signs, symptoms, or clinical indicators of reduced blood flow; the results are needed to guide your medical or surgical care; and the test isn’t duplicating information already obtained from another procedure.
This means screening ordered purely for a patient with no symptoms and no documented risk factors may not be covered. However, if your provider documents specific risk factors or findings on physical exam (a weak pulse in the foot, for example), the test is more likely to qualify. If you’re concerned about cost, ask your provider’s office to verify coverage before the appointment.
What Happens After an Abnormal Result
A low ABI doesn’t automatically mean you need surgery or a procedure. For most people with mild to moderate PAD, the first steps involve managing the underlying risk factors that caused the plaque buildup in the first place. That typically means a combination of blood pressure control, cholesterol management, blood sugar regulation if you have diabetes, smoking cessation, and a structured walking program.
Supervised exercise programs, where you walk until leg pain starts, rest, then walk again, have been shown to significantly improve the distance people with PAD can cover comfortably. Your provider will also look at your overall cardiovascular risk, since PAD diagnosed through screening is a strong signal that your coronary and carotid arteries may be narrowing too. You can expect more frequent follow-up visits and, in some cases, additional imaging to check blood flow in other parts of the body.
For people with severe disease or worsening symptoms despite conservative treatment, procedures to open or bypass blocked arteries become an option. But the entire point of screening is to find PAD before it reaches that stage, when lifestyle changes and medication can slow or halt progression.