Final answer:
Using a cuff that is too tight or too small can cause a high blood pressure reading due to excessive constriction of the arm. The correct cuff size is necessary for accurate blood pressure measurement with a sphygmomanometer.
Step-by-step explanation:
A cuff that is too tight or too small may indeed give a high reading when measuring blood pressure. This is because such a cuff can constrict the arm too much, increasing the pressure needed to shut off blood flow through the artery. It is important that the medical technician uses a sphygmomanometer appropriately sized for the patient's arm. When using a blood pressure cuff, it should be wrapped around the arm at the level of the heart, inflating it to a point where it is snug but not excessively tight.
If the cuff's size doesn't match the arm's circumference, it can lead to inaccuracies in the blood pressure measurement. Since the criterion for detecting the systolic and diastolic pressure involves listening for heartbeats with a stethoscope, an incorrect cuff size can therefore affect the pressure reading observed on the manometer. Therefore, ensuring the correct cuff size is essential to obtain an accurate blood pressure measurement.