Blood pressure measurement

Patent Granted Arterial pressure is most commonly measured via a sphygmomanometer, which historically used the height of a column of mercury to reflect the circulating pressure.[33] Blood pressure values are generally reported in millimetres of mercury (mm Hg), though aneroid and electronic devices do not contain mercury. For each heartbeat, blood pressure varies between systolic and diastolic pressures. Systolic pressure is peak pressure in the arteries, which occurs near the end of the cardiac cycle when the ventricles are contracting. Diastolic pressure is minimum pressure in the arteries, which occurs near the beginning of the cardiac cycle when the ventricles are filled with blood. An example of normal measured values for a resting, healthy adult human is 120 mm Hg systolic and 80 mm Hg diastolic (written as 120/80 mm Hg, and spoken as "one-twenty over eighty").