血压
xiěyā · HSK 7
pressure
🩸 血压 = 血 (blood) + 压 (pressure) = blood pressure
血 means blood and 压 means to press or pressure; together they name the force of blood pushing on vessel walls. The 压 in 血压 is the same press found in 压力 (pressure).
血 — drop 丿 over dish 皿
Originally a pictograph of a sacrificial vessel (皿) with a drop of blood inside, marking the offering of blood in ancient rituals. The small stroke on top represents the blood itself. Over time it broadened from ritual blood to blood in general.
压 — 厂 (cliff) + 土 (earth) below
压 is the simplified form of 壓. The original character combined 厭 (phonetic, suggesting 'yā') with 土 (earth) to mean pressing or weighing down on the ground. The modern simplified form keeps 厂 (a cliff or overhang) above 土, visually evoking earth being pressed under a heavy mass.