the pressure of the blood in the circulatory system, often measured for diagnosis since it is closely related to the force and rate of the heartbeat and the diameter and elasticity of the arterial walls.- When your heart beats, it squeezes and pushes blood through your arteries to the rest of your body. This force creates pressure on those blood vessels, and that's your systolic blood pressure. The diastolic reading, or the bottom number, is the pressure in the arteries when the heart rests between beats. This is the time when the heart fills with blood and gets oxygen. A normal diastolic blood pressure is lower than 80.
When your doctor takes your blood pressure, it's expressed as a measurement with two numbers, with one number on top "systolic" and one on the bottom "diastolic", like a fraction. For example, 120/80 mm Hg. The top number refers to the amount of pressure in your arteries during the contraction of your heart muscle.
