Systolic blood pressure

Systolic blood pressure is related to the strength of the heart muscle as it pushes blood into the arterial system, and more importantly, to the elasticity of the arteries -- their ability to expand and contract with changes in pressure. Thus, if the arteries are flexible and give easily as the heart beats, systolic pressure will not be excessively high. This is characteristic of young persons who often have a systolic pressure of 110, or even less. Such low pressure is not clinically significant. A medical school teacher may remark that the only thing to do for such individuals is to offer congratulations.

As we grow older, the blood vessel walls tend to stiffen, and arteriosclerosis (hardening of the arteries) may aggravate the normal loss of elasticity. Loss of elasticity causes a higher systolic pressure as the heart tries to force a normal amount of blood into the unyielding arteries. After the age of 55, systolic pressure tends to be higher, and a pressure of 150 to 160 is not unusual due solely to the normal loss of elasticity in aging tissues.