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Understanding high blood pressure

High blood pressure means your blood is pushing harder against blood vessel walls instead of smoothly flowing through.

Blood pressure is the force of the blood against the walls of arteries.

The heart pumps blood through the aorta, the main artery of the heart. The aorta branches off into other arteries, arterioles (small arteries) and capillaries, which carry blood throughout the body.

Arteries can best transport blood when they're open, supple and elastic. If they're narrowed or hardened, it's more difficult for blood to flow through them. That means the pressure on the walls of the arteries increases, and the heart has to work harder to move blood. When the pressure in the arteries rises above normal and stays there, you have high blood pressure. 

What should your numbers be?

Blood pressure is always expressed in two numbers, which are measurements of millimeters of mercury (mm Hg). The higher number, called systolic pressure, is your blood pressure when your heart beats. The lower number, known as diastolic pressure, is your blood pressure when your heart rests.

The readings are stated as systolic over diastolic pressure, such as 120/80. According to the American Heart Association, normal blood pressure is below 120 systolic and 80 diastolic.

The risk of death from heart attack and stroke increases progressively with higher levels of blood pressure. Even people whose pressure is only slightly above normal are at risk. People with blood pressure readings of 120 to 129 systolic and less than 80 diastolic are in a category known as elevated blood pressure. These people should consult their doctors about making lifestyle changes to lower their blood pressure before they develop hypertension, which means blood pressure readings consistently at or above 130 systolic or 80 diastolic.

Reviewed 7/29/2022

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