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Blood Pressure Basics
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Blood Pressure Basics
Blood pressure is the amount of force exerted by the blood as it moves against the vessel walls, and is carefully regulated by the body. It depends on the volume of your blood and the stiffness or elasticity of your blood vessels.
Why are there two numbers?
Your blood pressure is usually written as systolic/diastolic (eg, 120/80 mm Hg). Systolic (the top number) pressure is the amount of pressure on your blood vessels during your heartbeat. Diastolic (the bottom number) pressure is the amount of pressure when the heart relaxes between beats. Blood pressure numbers are sometimes followed by the notation "mm Hg". This stands for millimeters of mercury, and is the unit of measure used in a blood pressure gauge.
What is normal blood pressure?
Normal blood pressure for most adults is less than 120/80 mm Hg. High blood pressure occurs when there is too much force against your blood vessel walls. Most people will experience high blood pressure at some point in their lives, especially as age increases. High blood pressure medication, along with lifestyle changes, is recommended if either the systolic or diastolic number is at or above 140/90 mm Hg, or 130/80 mm Hg if you have diabetes or chronic kidney disease.