Ankle-Brachial Index (ABI) Calculator
The Ankle-Brachial Index (ABI) is a simple, non-invasive test that compares the blood pressure measured at your ankle with the blood pressure measured at your arm. This ratio helps healthcare providers assess your risk for Peripheral Artery Disease (PAD), a condition where narrowed arteries reduce blood flow to your limbs.
Enter the systolic blood pressure readings (the top number in a blood pressure reading) for both ankles and arms in millimeters of mercury (mmHg) to calculate your ABI for each leg.
Right Leg Pressures (mmHg)
Left Leg Pressures (mmHg)
Arm Pressures (mmHg)
Results:
Right ABI:
Interpretation (Right Leg):
Left ABI:
Interpretation (Left Leg):
Understanding the Ankle-Brachial Index (ABI)
The Ankle-Brachial Index (ABI) is a crucial diagnostic tool for detecting Peripheral Artery Disease (PAD). PAD occurs when plaque builds up in the arteries that carry blood to your head, organs, and limbs, most commonly affecting the legs. This can lead to pain, numbness, and other serious complications if left untreated.
How is ABI Measured?
During an ABI test, a healthcare professional will:
- Measure the systolic blood pressure in both of your arms.
- Measure the systolic blood pressure in two arteries in each ankle (dorsalis pedis and posterior tibial).
- Use a Doppler ultrasound device to listen to your pulse and ensure accurate readings.
The highest ankle pressure for each leg is then divided by the highest arm pressure to get the ABI for that leg.
Interpreting Your ABI Results
The ABI value provides insight into the health of your arterial blood flow. Here's a general guide to interpreting the results:
- ABI > 1.30: Non-compressible arteries. This often indicates calcification of the arteries, which can be common in individuals with diabetes or kidney failure. It means the arteries are stiff and cannot be compressed, making the reading artificially high. Further evaluation is usually needed.
- ABI 1.00 – 1.30: Normal. This range suggests healthy blood flow and no significant narrowing of the arteries.
- ABI 0.91 – 0.99: Borderline. This indicates a borderline risk of PAD. Lifestyle changes and monitoring may be recommended.
- ABI 0.41 – 0.90: Mild to Moderate PAD. This range suggests some degree of arterial narrowing, which may cause symptoms like leg pain during exercise (claudication).
- ABI 0.00 – 0.40: Severe PAD. This indicates significant arterial blockage, often associated with severe symptoms, even at rest, and a higher risk of complications.
What to Do with Your Results
This calculator is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider for any health concerns or before making any decisions related to your health or treatment. The interpretation provided is a general guide; a medical professional can provide a personalized assessment based on your full medical history and other clinical findings.