Fifty million people in the US and one billion people worldwide have high blood pressure. This overwhelming prevalence may lead a person to think, “Just about everybody has high blood pressure so it can’t be that big of a deal.” But that is hardly the truth. The higher a person’s blood pressure, the greater the risk of heart attack, heart failure, stroke, and kidney disease. The World Health Organization (WHO) estimates that one in every eight deaths is caused by hypertension—it is the third leading killer in the world.

Because of hypertension’s serious health consequences and its high prevalence, a coalition of blood pressure experts – representing 46 major professional, public, voluntary, and federal organizations and agencies—periodically review all the relevant medical literature and issue guidelines and advisories on the prevention, detection, evaluation, and treatment of high blood pressure. This panel’s latest publication, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (the JNC 7 Report), presents several new recommendations, including a crucial change to the way blood pressure readings are classified. The findings of this report were published in the May 21, 2003 issue of the Journal of the American Medical Association .

About the study

The expert panel’s previous report was published in 1997. Since that time, many new observational studies and clinical trials involving hypertension have been published. This fact was a major impetus in issuing new guidelines. In creating the JNC 7 Report, an extensive review of peer-reviewed scientific literature from January 1997 through April 2003 was conducted. Five writing teams created 24 drafts, which were reviewed repeatedly. The executive committee met on six separate occasions and produced the final report, which was approved by the National High Blood Pressure Education Program Coordinating Committee.

The findings

In the previous guidelines, the JNC 6, blood pressure less than 130/90 mm Hg was classified as normal. In JNC 7, a person with a systolic blood pressure (top number) of 120-139 mm Hg or a diastolic blood pressure (bottom number) of 80-89 mm Hg should be considered prehypertensive with an increased risk of progressing to hypertension. People who fall into this category can reduce their long-term risk of hypertensive complications by adopting health-promoting lifestyle modifications.

The following table presents the new JNC 7 blood pressure classifications.

New Blood Pressure Classification of Blood Pressure (BP) for Adults Age 18 or Older
BP ClassificationSystolic BP (mm Hg)Diastolic BP (mm Hg)
Normal< 120< 80
Stage 1 hypertension140-15990-99
Stage 2 hypertension≤160≥100

Some of the study’s other key findings include:

  • If you are 50 or older, systolic blood pressure greater than 140 mm Hg is a more important cardiovascular risk factor than an elevated diastolic blood pressure.
  • Starting at a blood pressure reading of 115/75 mm Hg, each incremental increase of 20/10 mm Hg doubles your risk of cardiovascular disease.
  • People who have normal blood pressure at age 55 have a 90% lifetime risk of developing high blood pressure.
  • Thiazide-type diuretics should be used in drug treatment for most patients with uncomplicated hypertension, either alone or in combination with drugs from other classes. (Interestingly, thiazide-type diuretics are the least expensive antihypertensive drugs, but remain underused.)
  • Most people with hypertension will require two or more antihypertensive medications to achieve target blood pressure.
  • The most effective therapy will only control hypertension if a person is motivated to follow it.

How does this affect you?

Because almost one-third of Americans who have high blood pressure don’t even know it, you should have your blood pressure checked regularly. In order to ensure an accurate blood pressure reading, you should be seated quietly in a chair (not on an examination table) for at least five minutes with your feet on the floor and you arm supported at heart level. Three separate readings are necessary before making the diagnosis of hypertension or prehypertension. Ask your doctor to write down your blood pressure to help you remember it.

If your blood pressure is in the prehypertensive or hypertensive range, talk with your doctor about what therapy is best for you and stick with it. As noted above, even the most effective blood pressure-reduction therapy won’t work if you don’t adhere to it.

The JNC 7 Report recommends lifestyle modifications that have been shown to reduce blood pressure, enhance antihypertensive drug efficacy, and decrease cardiovascular risk. They are: