Translating Blood Pressure Numbers
Blood pressure is
commonly measured by wrapping an inflatable cuff around the
upper arm.
Air is pumped into the cuff until circulation is cut off; when a
stethoscope
is placed over the cuff , there is silence. Then as the air is
slowly
let out of the cuff, blood begins to flow again and can be heard
through
the stethoscope. This is the point of greatest pressure (called
Systolic),
and is usually expressed as how high it forces a column of
mercury to
rise in a tube.
At its highest normal pressure, the heart would send
a column of mercury to a height of about 120 millimeters. At
some point,
as more and more air is let out of the cuff, the pressure
exerted by
the cuff is so little that the sound of the blood pulsing
against the
artery walls subsides and there is silence again. This is the
point of
lowest pressure (called Diastolic), which normally raises the
mercury to about 80 millimeters.
Know Your Numbers
It
is crucial to "Know Your Numbers" with respect to Blood
Pressure.
Life-threatening complications can develop over a course
of years
when hypertension exists. Increased pressure on the inner
walls
of blood vessels make the vessels less flexible over time
and more
vulnerable to the buildup of fatty deposits in a process
known
as atherosclerosis. Hypertension also
forces the heart to work harder to pump adequate blood
throughout
the body. This extra work causes the muscles of the heart
to enlarge,
and eventually the enlarged heart becomes inefficient in
pumping
blood. An enlarged heart may lead to heart failure, in
which the
heart can not pump enough blood to meet the body's needs.
Systolic and Diastolic readings are important
diastolic pressure has
traditionally been emphasized because it is less subject to
fluctuations.
However, recent studies have revealed that systolic pressure may
be as
significant a heart attack predictor as diastolic pressure.
Normal blood pressure
is thus usually said to be 120/80 (systolic/diastolic) or
less, measured
in millimeters of mercury (abbreviated as mm Hg). What do
blood pressure
numbers indicate? The higher (systolic) number represents the
pressure
while the heart is beating. The lower (diastolic) number
represents
the pressure when the heart is resting between beats.
The systolic
pressure is always stated first and the diastolic pressure
second.
For example: 122/76 (122 over 76); systolic = 122, diastolic =
76.
Blood pressure of less than 140 over 90 is considered a normal
reading
for adults.
A systolic pressure of 130 to 139 or a diastolic pressure
of 85 to 89 needs to be watched carefully. A blood pressure
reading
equal to or greater than 140 (systolic) over 90 (diastolic) is
considered
elevated (high).
Rating
Systolic
Diastolic
Optimal
<120
<80
Normal
<130
<85
High Normal
130-139
85-89
Hypertension
Stage 1
140-159
90-99
Hypertension
Stage 2
160-179
100-109
Hypertension
Stage 3
>179
>109
In some people,
the system that regulates blood pressure goes awry: arteries
throughout
the body stay constricted, driving up the pressure in the
larger blood
vessels. Sustained high blood pressure - above 140/90 mm Hg,
according
to most experts - is called hypertension. About 90 percent of
all people
with high blood pressure have "essential" hypertension -
meaning that it has no identifiable cause. In the remaining 10
percent
of cases, the elevated blood pressure is due to kidney
disease, diabetes,
or another disorder.
