A home blood pressure test allows you to keep track of your
blood pressure at home. Blood pressure is a measure of
the force of blood inside an artery.
Most people use an automatic device to measure blood pressure at home. This device works by inflating a cuff around the upper arm to temporarily stop the flow of blood in an artery. As air is slowly released from the cuff, the device records the pressure at which blood begins to flow again.
pressure is recorded as two measurements.
- The first number is the systolic pressure. Systolic
pressure represents the peak blood pressure that occurs when the heart
- The second number is the diastolic pressure. Diastolic pressure
represents the lowest blood pressure that occurs when the heart relaxes between
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").
Automatic blood pressure monitors
Automatic monitors, also called electronic or digital monitors, are battery-operated monitors that use a microphone to
detect blood pulsing in the artery. The cuff, which is wrapped around your upper arm, automatically inflates and deflates when you press the start button.
The type of blood pressure
monitor typically found in supermarkets, pharmacies, and shopping malls is an
Blood pressure monitors that measure your blood pressure in
your finger or your wrist are not usually accurate and are not
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
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 placing the stethoscope on the skin over the artery. You listen for the sound of the blood
beginning to flow through the artery again as air is released from the
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.
As the cuff pressure falls, the reading on the gauge when blood flow is
first heard is the systolic pressure. The reading on the gauge when blood flow can no longer
be heard is the diastolic pressure.
Ambulatory blood pressure monitors
An ambulatory blood pressure monitor is a small device that is worn throughout the day, usually
for 24 or 48 hours. The device takes your blood pressure automatically.
Your doctor might recommend this monitor if he or she thinks you have white-coat (or office) hypertension or if other methods do not give consistent results.