Instruction Manual

- Eng 23 -
English
ABOUT “BLOOD PRESSURE”
What is blood pressure?
The heart is a pump that circulates blood throughout your body. Blood is pumped
from the heart at a constant pressure into arteries. This pressure is called the
arterial blood pressure and represents, in general terms, your blood pressure. Blood
pressure is indicated by several kinds of pressures, including the systolic pressure
that occurs when the heart pumps blood, and the diastolic pressure that occurs
when blood returns to the heart.
Your blood pressure changes all the time.
Your blood pressure differs according to your age, gender and a range of other
factors. It is likely to be affected by your biorhythm during the day and by your
posture, physical activities, mental activities, level of stress and even by the air
temperature. The blood pressure of a healthy person generally varies within a day.
(Systolic) (Diastolic)
Artery
Left atrium
Left
ventricle
The artery wall
expands.
Contraction
Artery
Left atrium
Left
ventricle
Normal state is restored to
the artery wall.
Dilation
Systolic blood
pressure
Diastolic blood
pressure
Time of day
Blood pressure value (mmHg)
160
140
120
100
80
60
40
12 13 14 15 16 17 18 19 20 21 22 23 24 1 2 3 4 5 6 7 8 9 10 11
Sleeping
(Blood pressure values measured at fi ve-minute intervals through the day)
● Bevan AT, Honour AJ, Stott FH. Clin Sci 1969;36:329–44.
[Example of blood pressure variations within a day]