John Muir Health
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Blood pressure is the force exerted on the artery walls by the blood. The force is highest when the heart ejects or pumps the blood out of the left ventricle. This higher pressure is called the systolic blood pressure. As the heart relaxes and refills with blood, during diastole, the pressure in the arteries drops. This is the diastolic pressure. When the blood pressure is taken there are always two numbers, written as systolic/diastolic.

Blood pressure is dynamic and constantly changing due to internal and external stimuli. Blood pressure should be checked while you are quietly sitting. A single elevated blood pressure reading does not mean you have hypertension. Hypertension is diagnosed after several elevated readings. Elevated blood pressure should be discussed with your doctor. Blood pressure readings falling in Stage 3 to Stage 4 should be immediately reported to your doctor. High blood pressure works the heart harder and causes arteries to become less flexible. Sustained high blood pressure increases the risk of and can be a direct cause of heart attack, stroke and kidney failure.

Men, overweight individuals, and those with a family history of hypertension are more likely to have high blood pressure.

African-, Puerto Rican-, Cuban-, Philippine-, and Mexican-Americans are more likely to suffer from high blood pressure than white Americans.

Other risk factors include aging, smoking, sodium sensitivity, alcohol usage, oral contraceptive use, and physical inactivity.

To control blood pressure:

Blood Pressure Chart:

Category Systolic
mmHg
Diastolic
mmHg
Normal < 120 < 80
Pre Hypertension 120-139 80-89
Hypertension**
STAGE 1 (Mild) 140-159 90-99
STAGE 2 (Moderate) 160-179 100-109
STAGE 3 (Severe) 180-209 110-119
STAGE 4 (Very Severe) > 210 > 120

Blood Pressure Resources:
For guidelines and other information on blood pressure visit the National Heart, Lung and Blood Institute web site.