Which of the following statements is correct about blood pressure measurement technique?

• A. The cuff width should be about 40% of the arm circumference.
• B. The cuff width should be about 20% of the arm circumference.
• C. The cuff should be placed around the calf.
• D. The patient should be measured with the arm above heart level.

Answer: (A)

Accurate blood pressure hinges on using a cuff that fits the arm properly and positioning the limb correctly. The cuff width should be about 40% of the arm circumference. This sizing ensures the cuff compresses the artery evenly and yields a reading that reflects true arterial pressure. If the cuff is too narrow, the pressure needed to occlude the artery rises, making the reading falsely high. If the cuff is too wide, the reading can be falsely low.

Also important is placing the cuff on the upper arm, not the calf, and keeping the arm at heart level during measurement. The arm should be supported and relaxed, with the patient seated and the back supported and feet uncrossed. The cuff should encircle the arm and cover a substantial portion of its circumference to avoid errors.

So the statement about using a cuff width of about 40% of the arm circumference is the correct guidance.