Blood Pressure (BP) is the measure of the pressure exerted on the walls of the heart, arteries and capillaries as a result of cardiac contraction (the heart pumping). Blood pressure in a person is determined by the force of the cardiac contraction, the volume of blood and and the condition of the arteries (elasticity and extent to which they are blocked).

Blood pressure is measured on two levels Systolic and Diastolic. An inflatable blood pressure cuff is applied (normally to the upper arm) and inflated to well above blood pressure range. Air is gently bled out of the cuff while listening to an artery below the restriction of the cuff with a stethoscope. At the point that a pulse can just be heard is where systolic pressure is measured and diastolic pressure is measured when the pressure has been lowered to the point where the pulse can no longer be heard. Blood pressure is recorded as systolic/diastolic in mm Hg.

135/87 is regarded as the high end of normal, over that is regarded as high blood pressure. 120/80 is regarded as low normal - below that is regarded as low blood pressure.

Blood pressure varies significantly from person to person - the higher the pressure, the higher the risk of cardio-vascular disease or problems.