Ankle-Brachial Index (ABI) Calculator
Calculation Results:
'; outputHTML += 'Right Ankle-Brachial Index (ABI): ' + rightABI.toFixed(2) + ' (' + rightABIInterpretation + ')'; outputHTML += 'Left Ankle-Brachial Index (ABI): ' + leftABI.toFixed(2) + ' (' + leftABIInterpretation + ')'; outputHTML += 'Note: This calculator provides an estimate. Always consult a healthcare professional for diagnosis and treatment.'; resultDiv.innerHTML = outputHTML; } /* Basic styling for the calculator – can be customized */ .calculator-container { background-color: #f9f9f9; border: 1px solid #ddd; padding: 20px; border-radius: 8px; max-width: 600px; margin: 20px auto; font-family: Arial, sans-serif; } .calculator-container h2 { text-align: center; color: #333; margin-bottom: 20px; } .calculator-input-group { margin-bottom: 15px; } .calculator-input-group label { display: block; margin-bottom: 5px; font-weight: bold; color: #555; } .calculator-input-group input[type="number"] { width: calc(100% – 22px); padding: 10px; border: 1px solid #ccc; border-radius: 4px; box-sizing: border-box; } .calculator-container button { display: block; width: 100%; padding: 12px; background-color: #007bff; color: white; border: none; border-radius: 4px; font-size: 16px; cursor: pointer; transition: background-color 0.3s ease; } .calculator-container button:hover { background-color: #0056b3; } .calculator-result { margin-top: 20px; padding: 15px; border: 1px solid #e0e0e0; border-radius: 4px; background-color: #e9f7ef; color: #333; } .calculator-result h3 { color: #28a745; margin-top: 0; } .calculator-result p { margin-bottom: 5px; line-height: 1.5; } .calculator-result strong { color: #0056b3; }Understanding the Ankle-Brachial Index (ABI)
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 comparison helps healthcare professionals assess the blood flow in your legs and feet, primarily to detect Peripheral Artery Disease (PAD).
What is Peripheral Artery Disease (PAD)?
PAD is a common circulatory problem in which narrowed arteries reduce blood flow to your limbs, most commonly your legs. When you develop PAD, your legs don't receive enough blood flow to keep up with demand, causing symptoms like leg pain when walking (claudication). PAD is often a sign of more widespread arterial disease, which can increase your risk of heart attack and stroke.
How is ABI Measured?
The ABI test is performed using a regular blood pressure cuff and a Doppler ultrasound device. Blood pressure is measured in both arms and both ankles. The highest systolic pressure (the top number in a blood pressure reading) from each arm is used, and the highest systolic pressure from each ankle is also recorded. The ABI for each leg is then calculated by dividing the highest ankle systolic pressure for that leg by the highest brachial (arm) systolic pressure.
Interpreting Your ABI Results
The ABI value provides crucial information about the health of your arteries. Here's a general guide to interpreting the results:
- ABI > 1.30: Non-compressible arteries. This often indicates calcification of the arteries, which can occur in individuals with advanced diabetes or chronic kidney disease. In such cases, the ABI may be falsely elevated, and further tests might be needed.
- ABI 1.00 – 1.29: Normal. This range suggests healthy blood flow and no significant narrowing of the arteries.
- ABI 0.91 – 0.99: Borderline. While not definitively abnormal, a borderline ABI suggests a higher risk for PAD and warrants close monitoring and lifestyle modifications.
- ABI ≤ 0.90: Abnormal (Peripheral Artery Disease – PAD). An ABI in this range indicates that there is significant narrowing or blockage in the arteries of the legs. The lower the number, the more severe the PAD.
- ABI < 0.50: Severe Peripheral Artery Disease (PAD). This indicates critical limb ischemia, a severe form of PAD that can lead to non-healing wounds, gangrene, and potentially amputation if not treated.
Why is ABI Important?
Early detection of PAD through ABI testing is vital because it allows for timely intervention, which can prevent the progression of the disease and reduce the risk of serious complications. It also serves as an indicator for systemic atherosclerosis, prompting further cardiovascular risk assessment.
Disclaimer
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.