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.
[Example of blood pressure variations within a day]
160
140
120
100
80
60
40
12 13 14 15 16 17 18 19 20 21 22 23 24 1
BLOOD PRESSURE Q&A
Q
Why is the blood pressure measured at home different from that measured by the
physician or at a hospital?
A
Your blood pressure may vary due to exercise, the ambient temperature or your mental
state. When you have a physician or nurse measure your blood pressure, the pressure
value is likely to be 10 to 20 mmHg higher than usual due to anxiety and/or stress.
Knowing what affects your blood pressure helps you to better monitor your health.
Q
Why does the blood pressure obtained vary with measurement?
A
Our blood pressure is adjusted by automatic nerve function. Blood pressure differs
with every heart beat. We are likely to think that our blood pressure is constant, but
it varies if you take measurements in repetition. Blood pressure is susceptible to the
time of day, such as morning and afternoon, season and atmospheric temperature.
In addition, blood pressure is easily affected by mental stress or emotional ups and
downs. It tends to increase when you feel tension or decrease when you are relaxed.
Q
What is the benefit of measuring my blood pressure at home?
A
Blood pressure measurements taken at home give reliable data as they can be taken
when you are in a stable and relaxed condition. Physicians place considerable importance
on blood pressure measurements taken at home. You should measure your blood
pressure at the same time each day and record the variations in your blood pressure.
Always consult your physician for an interpretation of your blood pressure
readings and to determine the proper treatment.
(Systolic)
Left
atrium
Left
ventricle
Sleeping
2
3
4
5
6
7
8
Time of day
- Eng 14 -
(Diastolic)
Artery
The artery wall
expands.
Contraction
(Blood pressure values
Systolic blood
pressure
measured at five-minute
intervals through the day)
● Bevan AT, Honour AJ, Stott
FH. Clin Sci 1969;36:329–44.
Diastolic blood
pressure
9 10 11
Artery
Left atrium
Normal state is
Left
ventricle
restored
to the artery wall.
Dilation