What does mm Hg stand for in the context of blood pressure measurement?

In the context of blood pressure measurement, mm Hg stands for millimeters of mercury. This unit is used to quantify the pressure exerted by blood within the arteries, indicating how much force the blood is applying against the walls of the vessels during different phases of the heartbeat.

Historically, mercury was used in barometers to measure atmospheric pressure, and this traditional measurement has been adapted for various medical applications, including blood pressure measurement. The pressure is measured in millimeters, where it expresses how high the mercury column rises in a calibrated tube as the blood exerts pressure against it.

This method provides a standardized way to communicate blood pressure levels, allowing healthcare professionals to assess cardiovascular health efficiently. Understanding this unit helps in interpreting blood pressure readings, which are usually presented as two numbers, systolic over diastolic, both measured in mm Hg.