Blood pressure

Blood pressure, pressure of the blood upon the walls of the arteries as it is pumped from the heart. The pressure is strongest at the left ventricle of the heart but can be felt pulsing at various points on the body. The pulsing corresponds to the force and rhythm of the heart's pumping action, and it can be measured to determine blood pressure. An instrument called a sphygmomanometer is used to ascertain the pressure at the brachial artery of the forearm, just above the elbow.

Blood pressure is recorded by 2 figures written as a fraction. The numerator indicates the systolic, or maximum, pressure produced by the heart; the denominator indicates the diastolic, or lower, pressure produced by the heart, which results in the least pressure upon the artery. “130/90,” for example, is read as “130 over 90.” Hypertension and stroke are disorders accompanied by high blood pressure.

See also: Blood.