What happens if a blood pressure cuff is too small for the patient?

When a blood pressure cuff is too small for a patient, it typically leads to the overestimation of both systolic blood pressure (SBP) and diastolic blood pressure (DBP). This occurs because a smaller cuff requires a higher pressure to occlude the artery, which results in higher readings than the patient's actual blood pressure. The cuff exerts excessive pressure on the arm, which can cause the artery to narrow more than it would with a correctly sized cuff, creating artificially elevated values.

Proper cuff size is essential for accurate blood pressure measurements. A cuff that is appropriately sized ensures that the pressure exerted on the arm correlates appropriately with the arterial pressure being measured, yielding accurate and reliable readings. Therefore, in a clinical setting, it is critical for practitioners to select the right cuff size according to the patient's arm circumference, ensuring the measurements reflect their true blood pressure status.