What is the recommended cuff width and bladder length relative to the arm?

• A. Cuff width about 40% of arm circumference; bladder length about 80% of arm circumference.
• B. Cuff width about 20%; bladder length about 50%.
• C. Cuff width about 60%; bladder length about 90%.
• D. Cuff width about 50%; bladder length about 120%.

Answer: (C)

Accurate blood pressure relies on cuff sizing that matches the size of the arm. The cuff width should be about 40% of the arm’s circumference, and the bladder length should encircle roughly 80% of the arm’s circumference. This sizing ensures the cuff applies pressure evenly and occludes the brachial artery reliably without causing excessive squeeze or insufficient coverage. If the cuff is too narrow, readings tend to be falsely high because more pressure is needed to stop blood flow. If the cuff is too wide, readings can be falsely low or unreliable because the pressure is distributed over too broad an area. The bladder length needs to be long enough to encircle most of the arm (about 80%) to avoid partial occlusion and variability. So, the recommended proportions are a cuff width near 40% of arm circumference and a bladder length near 80% of arm circumference.