n. the pressure exerted by blood against the walls of the arteries, expressed in millimeters of mercury. This is measured as the pressure when the heart is contracting (systolic) over the pressure when the heart is relaxing (diastolic). It is affected by age, activity, and health, and it varies along with heart rate, elasticity of the arteries, and cholesterol levels. See hypertension- hypotension.
BLOOD PRESSURE: "The normal blood pressure reading for a healthy individual at rest is around 120/80 mm Hg."