Blood pressure refers to the force exerted by circulating blood on the walls of blood vessels, and constitutes one of the principal vital signs. The term blood pressure generally refers to arterial blood pressure, i.e., the pressure in the larger arteries. Blood pressure is most commonly measured via a sphygmomanometer, which uses the height of a column of mercury to reflect the circulating pressure. Although many modern blood pressure devices no longer use mercury, blood pressure values are still universally reported in millimetres of mercury (mmHg). It consists of two parts: the systolic pressure and the diastolic pressure.

　　血壓是指血液循環(huán)時作用于血管壁的壓力，為生命體征之一。血壓這一術(shù)語一般是指動脈血壓，即大動脈血壓。最常用的測壓工具是血壓計(jì)，它根據(jù)水銀柱的高度來反映血液循環(huán)時所產(chǎn)生的壓力。雖然現(xiàn)在的很多血壓器具已不再使用水銀，但毫米汞柱（mmHg）依然是世界通用的測壓單位，它包括兩個部分：包括收縮壓和舒張壓

　　The systolic pressure is defined as the peak pressure in the arteries, which occurs near the beginning of the cardiac cycle; the diastolic pressure is the lowest pressure (at the resting phase of the cardiac cycle). The average pressure throughout the cardiac cycle is reported as mean arterial pressure; the pulse pressure reflects the difference between the maximum and minimum pressures measured. form www.genyda.com

　　心動周期開始時動脈出現(xiàn)的最高值為收縮壓，心動周期靜息期出現(xiàn)的最低壓為舒張壓，心動周期全過程中的平均壓力為平均動脈壓。最高和最低值之差為脈搏壓。

　　Typical values for a resting, healthy adult human are approximately 120 mmHg systolic and 80 mmHg diastolic (written as 120/80 mmHg, and spoken as "one twenty over eighty"). These measures of blood pressure are not static, but undergo natural variations from one heartbeat to another and throughout the day (in a circadian rhythm); they also change in response to stress, nutritional factors, drugs, or disease. Hypertension refers to blood pressure being abnormally high, as opposed to hypotension, when it is abnormally low.

　　健康成人靜息時的典型血壓約為收縮壓120mmHg，舒張壓80mmHg，寫作120/80 mmHg，血壓值并非靜止不變，一天之間（生理節(jié)律）、前后次搏動都會自然而然地有所變化，緊張、營養(yǎng)因素、藥物或疾病等也會導(dǎo)致其變化。血壓超出正常為高血壓，與低血壓相對，后者是指血壓低于正常值。

　　Blood pressures can be measured invasively or non-invasively. The former is usually restricted to a hospital setting. The latter is simpler and quicker and less unpleasant and painful for the patient, using a stethoscope, a sphygmomanometer, and a cuff of appropriate size.

　　測量血壓有兩種方法：侵入式和非侵入式。前者嚴(yán)格限于醫(yī)院，后者則較簡單快捷，病人的不適及痛苦也小，通常包括聽診器、血壓計(jì)和一個大小合適的袖袋。