Physics of Blood Pressure
When visiting a clinic, a patient usually gets a blood pressure reading. High blood pressure, hypertension, can warn of impending cardiovascular disease. Excessively low blood pressure can prevent blood from flowing to higher portions of the body, including the brain. Pressure is a basic physical quantity. How does physics apply to blood pressure?PressureThe pressure on a surface is the total force acting on the surface divided by the surface's area.Pressure = Force/Area.Pressure is usually measured in newtons per square meter (often called pascals) or in pounds per square inch. Pressure is also often measured in millimeters of mercury (mm HG), a unit that originated from old-fashioned mercury barometers. The conversion factor is:Further ReadingWilson, J.D., Buffa, A.J., and Lou, B., College Physics 6th ed., Pearson, 2007.