What position should the arm be in for an accurate blood pressure reading?

For an accurate blood pressure reading, the arm should be positioned at heart level. This is crucial because the pressure in the arteries can be affected by gravity. When the arm is at heart level, it ensures that the readings reflect the true pressure within the cardiovascular system as it relates to the heart.

If the arm is positioned higher than heart level, it may lead to a falsely low blood pressure reading because the hydrostatic pressure could reduce the reading. Conversely, if the arm is lower than heart level, it may produce a falsely high reading, as the weight of the blood could increase the pressure detected by the blood pressure cuff. Positioning the arm at heart level helps to eliminate these variances, allowing for a more accurate measurement of an individual's blood pressure.