Answer:This is because the height of the patient's arm in relation to their heart affects the accuracy of the reading.
When the arm is positioned below heart level, such as when the arm is hanging down at the patient's side, the blood pressure reading will be falsely elevated. This is because gravity makes it harder for the heart to pump blood to the arm, which causes the blood vessels in the arm to constrict, and the blood pressure reading to increase.
Conversely, when the arm is positioned above heart level, such as when the arm is held up in the air, the blood pressure reading will be falsely low. This is because the heart has to work less to pump blood to the arm, which causes the blood vessels in the arm to dilate, and the blood pressure reading to decrease.
Therefore, positioning the patient's arm at heart level ensures that the blood pressure reading is as accurate as possible.
Step-by-step explanation: