blood pressure science definition

The pressure of the blood in the vessels, especially the arteries, as it circulates through the body. Blood pressure varies with the strength of the heartbeat, the volume of blood being pumped, and the elasticity of the blood vessels. Arterial blood pressure is usually measured by means of a sphygmomanometer and reported in millimeters of mercury as a fraction, with the numerator equal to the blood pressure during systole and the denominator equal to the blood pressure during diastole. See more at hypertension, hypotension.