Test Overview
A home blood pressure test allows you to keep track of your
at home. Blood pressure is a measure of
the force of blood inside an artery. A blood pressure measurement is taken by
temporarily stopping the flow of blood in an artery (usually by inflating a
cuff around the upper arm) and then listening for the sound of the blood
beginning to flow through the artery again as air is released from the
cuff.
As blood flows through the artery, it can be heard through a
placed on the skin over the artery. Blood
pressure is recorded as two measurements.
- The reading on the gauge when blood flow is
first heard is called the systolic pressure. Systolic
pressure represents the peak blood pressure that occurs when the heart
contracts.
- The reading on the gauge when blood flow can no longer
be heard is the diastolic pressure. Diastolic pressure
represents the lowest blood pressure that occurs when the heart relaxes between
beats.
These two pressures are expressed in millimeters of mercury
(mm Hg) because the original devices that measured blood pressure used a column
of mercury. Blood pressure measurements are recorded as systolic/diastolic (say
"systolic over diastolic"). For example, if your systolic pressure is 120 mm Hg
and your diastolic pressure is 80 mm Hg, your blood pressure is recorded as
120/80 (say "120 over 80").
Types of blood pressure monitors
The two general
types of blood pressure monitors commonly available are manual and
automatic.
Manual blood pressure monitors
Manual models are
similar to those that your doctor might use to take your blood pressure. Called
a sphygmomanometer, these devices usually include an arm cuff, a squeeze bulb
to inflate the cuff, a stethoscope or microphone, and a gauge to measure the
blood pressure.
Blood pressure is displayed on a circular dial
with a needle. As the pressure in the cuff rises, the needle moves clockwise on
the dial. As the cuff pressure falls, the needle moves counterclockwise.
Automatic (also called electronic or digital) blood pressure monitors
Electronic battery-operated monitors use a microphone to
detect blood pulsing in the artery. You do not need to listen with a
stethoscope. The cuff, which is attached to your wrist or upper arm, is
connected to an electronic monitor that automatically inflates and deflates the
cuff when you press the start button.