Forearm or thigh BP readings are less standard because:

• A. They require standardized cuff sizes
• B. They are not as routinely validated and have less standard reference ranges
• C. They are always more accurate
• D. They are not as standard as upper-arm measurements

Answer: (C)

The key idea is that where you measure blood pressure affects how reliable and comparable the result is. Upper-arm measurements are the standard because they have the most evidence behind them, with well-established validation, cuff sizes, and reference ranges across populations. Forearm or thigh readings introduce more variability for several reasons: they often require different cuffs and techniques, the exact limb position and height can change the reading, and there are far fewer large studies that define normal or hypertensive values for those sites. Because of this, forearm and thigh measurements are not as routinely validated and do not have as consistent reference ranges, making them less standardized. They are not inherently more accurate; the lack of standardization and validation is what makes them less reliable for general use, though they can be useful in specific situations when upper-arm measurement isn’t possible.