A New Definition of “Normal” Blood
Find out whether you have “prehypertension,” and
if so, what you can do to reduce your risk of developing full-blown
You’ve been getting your blood pressure checked
regularly, and your readings are consistently below 130/85 mm
to previous guidelines from the Joint National Committee on Prevention,
Detection, Evaluation, and Treatment of High Blood Pressure,
which were released in 1997, you had normal blood pressure. Now,
according to the committee’s newest recommendations, you
might fall into a new category called prehypertension. This classification
was created to help motivate both doctors and their patients
to take important steps to prevent hypertension and to reduce
the risk of cardiovascular events, such as heart attacks and
Blood Pressure Classification: The Old vs. the New
to the old recommendations, “optimal” blood
pressure was a systolic pressure less than 120 mm Hg and a diastolic
pressure lower than 80 mm Hg. People with these values now fall
into the new “normal” category. The previous categories
of “normal” (systolic 120 to 129 mm Hg or diastolic
80 to 84 mm Hg) and “high-normal” (systolic 130 to
139 mm Hg or diastolic 85 to 89 mm Hg) have been combined into
the new “prehypertension” category. Therefore, prehypertension
is defined as a systolic blood pressure between 120 and 139 mm
Hg or a diastolic blood pressure of 80 to 89 mm Hg.
about the risks associated with elevated blood pressure levels
prompted experts to update the old blood pressure classifications. “We
have found that damage to the arteries begins at fairly low blood
pressure levels—levels previously considered ‘normal,’” Aram
V. Chobanian, M.D., the committee’s chair, said at a press
conference at which the guidelines were released. (The guidelines
were later published in May 2003 in the Journal of the American
The guidelines point out that the risks
of health problems like heart attacks, strokes, heart failure,
and kidney disease begin
to increase when blood pressure levels rise above 115/75 mm Hg.
For people 40 to 69 years of age, for example, every increase
of 20 mm Hg in systolic pressure or 10 mm Hg in diastolic pressure
above this threshold doubles the risk of dying of a stroke or
other cardiovascular event.
What To Do
The new guidelines don’t recommend that most
people with prehypertension take antihypertensive medication,
but they do
say that these individuals should use a combination of lifestyle
modifications to reduce their blood pressure, prevent the development
of hypertension, and lower their risk of cardiovascular events.
These modifications include losing weight, adopting a diet that
emphasizes fruits and vegetables, restricting sodium intake,
exercising, and consuming alcohol only moderately.
measures are also recommended for people with higher blood
pressure levels, including those on medication.
Using a combination of lifestyle modifications reduces blood
pressure more than using only some of them.
Still, certain people
with prehypertension should be treated with medication. According
to the guidelines, such persons
include those with diabetes or chronic kidney disease. These
may need medication to reduce their blood pressure to below
130/80 mm Hg.