What are the normal values for ankle-brachial index?

The normal values for the ankle-brachial index (ABI) indicate the ratio of the blood pressure in the lower legs to that in the arms. A healthy ABI is typically 0.90 and above, which suggests that there is adequate blood flow to the lower extremities. An ABI value this high is indicative of normal arterial function without significant vascular obstruction or peripheral artery disease.

Values less than 0.90 may suggest varying degrees of arterial insufficiency, with a value of less than 0.50 indicating severe peripheral artery disease, while values between 0.71 to 0.90 can indicate mild to moderate disease. Hence, the range of 0.90 and above is recognized as the threshold for normal ABI, making it the correct answer in this context. Understanding these values is crucial for accurately assessing vascular health in patients.