Blood Pressure is measured in ___________.

Blood pressure is measured in millimeters of mercury (mmHg) because this unit reflects the height of a column of mercury that is displaced by the pressure exerted by the blood within the arteries. The conventional use of mercury in sphygmomanometers, which are devices designed to measure blood pressure, historically stems from its predictable and reliable density characteristics, allowing for accurate readings.

In clinical practice, when health professionals record blood pressure, they indicate both systolic and diastolic pressures with values expressed in mmHg, such as 120/80 mmHg, which provides a clear and standardized method of communication regarding cardiovascular health. Other units listed, such as milligrams of mercury, millimoles per liter, and milligrams per liter, are not used in measuring blood pressure and do not apply to this context or the physiological parameters that blood pressure represents.