| KNOW THE NUMBERS|
pressure (top number) means the maximum pressure within your arteries during each heartbeat is great enough to eventually damage vessel walls.
pressure (bottom number) means your heart and blood vessels don't relax well between beats.
- Normal -- Less than 130/ 85 mm Hg
- High-normal -- 130 to 139/85 to 89 mm Hg
- Hypertension -- Consistently greater than 140/90 mm Hg
A desirable blood pressure level to achieve is 120 or less (systolic) over 80 or less (diastolic).
Blood pressure is a measurement of two factors. The top number is the systolic blood pressure, which measures the force the pumping heart exerts on the blood vessels. The lower number is the diastolic blood pressure, which is measured when the heart relaxes between beats.
"Isolated systolic blood pressure increases the risk of stroke, coronary heart disease, heart failure, and renal disease," said Dr. Edward Roccella of the NHLBI. "Lowering isolated systolic blood pressure has been shown to have benefits in reducing death and disability for these conditions."
The NHLBI advisory says everyone's blood pressure should be kept below 140/90.
But for those with high-risk conditions, the government agency advises more stringent control is needed. Diabetic patients should keep their pressure below 135/85 and those with heart or kidney failure should reduce their blood pressure as much as possible.
High blood pressure, or hypertension, is sometimes called the silent killer because many people never know they have it. Some 50 million Americans are affected.
"For the most part, people don't have symptoms," said Dr. Robert Phillips of Mt. Sinai School of Medicine. "Occasionally people might feel fatigued or have a slight headache, but for the most part, people don't feel anything."
Experts say that's why it is important for people to see their doctors regularly for a simple blood pressure check.
"The sooner we get people in the treatment, the sooner we get them to change their lifestyle to prevent blood pressures from rising, the better chance of preventing an event, which we call a heart attack, a stroke or kidney failure," Roccella said.
May is national high blood pressure month. The new advisory is published in the journal Hypertension, published by the American Heart Association. It is also available on the NHLBI Web site.
Medical Correspondent Steve Salvatore andReuters contributed to this report.
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Mayo Clinic Health Oasis
The National Heart, Lung and Blood Institute
Hypertension: Journal of the American Heart Association
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