Blood Pressure Lab Practice Test 2026 - Free Blood Pressure Practice Questions and Study Guide

Raising the arm above the level of the heart changes the local arterial pressure due to hydrostatic effects. Gravity causes the pressure in the arm to drop as the distance from the heart increases, so the arm becomes less well perfused and its local blood pressure is markedly lower than the central (heart) pressure. Because the cuff is measuring this lower, locally reduced pressure, obtaining a reliable reading becomes difficult—the pulse can be weak and the sounds (Korotkoff sounds) may be faint or harder to detect, leading to unreliable measurements. The cuff seal and the heart rate change are not the primary issues caused by arm elevation, and the main factor is the reduced perfusion from the increased height above the heart.