Measuring Your Blood Pressure

Blood pressure is a measurement of the force with which the heart pumps blood out into the arteries. The usual site for a blood pressure measurement is an artery in the arm because by this stage the opening through which the blood passes is narrow enough to actually resist the flow.

The instrument used to measure blood pressure consequently works on the idea that if you temporarily close the flow of blood through the artery, by inflating a special 'bandage' wound round the arm, the time taken for the flow to be re-established at full strength is a measurement of the force of the heartbeat.