What should a blood pressure cuff adequately cover on a patient's arm?

The correct answer is that a blood pressure cuff should adequately cover approximately 80% of the circumference of the arm. This ensures accurate and consistent readings. When the cuff encompasses this percentage of the arm's circumference, it can effectively compress the artery and produce reliable measurements of both systolic and diastolic blood pressure.

Covering too little of the arm’s circumference may lead to underestimation of blood pressure, as insufficient compression can allow the artery to remain partially open. Conversely, if a cuff were to cover the entire circumference of the arm, it may produce incorrect readings as well, either by oversizing the cuff or by applying excessive pressure that could occlude blood flow inappropriately.

Understanding the correct placement and sizing of the blood pressure cuff is crucial in clinical practice to avoid misdiagnosis and to ensure effective monitoring of a patient's cardiovascular health.