When measuring blood pressure, what unit is typically used?

The typical unit used when measuring blood pressure is millimeters of mercury (mmHg). This measurement originated from the early methods of assessing blood pressure using a mercury barometer, which translates the height of a column of mercury that correlates with the pressure exerted by the blood within the arteries.

Using mmHg provides a clear and standardized way to express blood pressure readings, which are commonly given in two figures: systolic over diastolic pressure (for example, 120/80 mmHg). This measurement is crucial in clinical settings for diagnosing and managing various cardiovascular conditions. Other units like pascals (Pa), liters (L), and atmospheres (atm) are not typically used for blood pressure measurement and are more relevant in different contexts such as physics and engineering.