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.
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).
|Low blood pressure,
also known as Hypotension, can, in rare cases be a sign of underlying
disease, but most of the time it is something to be grateful for. However,
one form of temporary low blood pressure can cause lightheadedness. Known
as orthostatic hypotension, it occurs when you stand up suddenly. Your
cardiovascular reflexes work quickly to prevent blood from pooling in your
ankles and legs, but a too rapid change in position may tax these reflexes,
especially in older people.
| Manual Blood
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