Blood pressure is the force of the blood pushing against the artery walls. The force is generated with each heartbeat as blood is pumped from the heart into the blood vessels. The size and elasticity of the artery walls also affect blood pressure; each time the heart beats pressure is created inside the arteries.
When blood is pumped out of the heart into the arteries, the pressure is at its greatest. The pressure falls in the arteries when the heart relaxes between beats. Two numbers are recorded when measuring blood pressure:
Both systolic and diastolic pressures are recorded as "mm Hg" (millimeters of mercury), representing how high the mercury column in the blood pressure cuff is raised by the pressure of the blood.
High blood pressure, also known as hypertension, increases the risk of heart attack and stroke. With hypertension, the arteries may have an increased resistance against the flow of blood, causing the heart to pump harder to circulate the blood. Usually, hypertension has no signs or symptoms, but you can check your blood pressure yourself or have it checked by your physician to know if you have hypertension.
The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) has determined two levels of high blood pressure for adults:
*These numbers are only to be used as a guide; consult your physician with any concerns.
Sometimes daily medication is needed to control hypertension. If you have hypertension, check your blood pressure regularly and see your physician to monitor the condition.