10
What is Blood Pressure?
When your heart beats, it pumps blood around your body to give it the energy and oxygen it needs. As the blood
moves, it pushes against the sides of the blood vessels. The strength of this pushing is your blood pressure. If
your blood pressure is too high, it puts extra strain on your arteries (and your heart) and this may lead to heart
attacks and strokes.
Having
high blood pressure (hypertension)
is not usually something that you feel or notice. It does not tend to
produce obvious signs or symptoms. The only way to know your blood pressure, is to have it measured using a
Blood Pressure Monitor.
Blood pressure is measured in
‘
millimetres of mercury
’
(mmHg) and is written as two numbers. For example, if
your reading is 120/80mmHg, your blood pressure is
‘120
over
80’.
Every blood pressure reading consists of two numbers or levels. They are shown as one number on
top of the
other.
The
top number is your
Systolic
blood pressure. The highest pressure when your heart beats and pushes the
blood round your body.
The bottom one is your
Diastolic
blood pressure. The lowest pressure when your heart rests between beats.
The blood pressure chart on the following page shows ranges of high, low
and
healthy blood pressure readings.
The blood pressure chart
is suitable for adults of any age as the level for high blood pressure does not change
with age.
Globally, around 40% of adults aged 25 and over had raised blood pressure in 2008 (World Health Organisation,
WHO).
What Do Blood Pressure Readings Mean?
Only
one
of the numbers has to be higher or lower than it should be
to count as either high blood pressure or
low blood pressure:
90 over 60
(90/60) or less:
You may have low blood pressure.
More than
90 over 60
(90/60) and less than 120 over 80 (120/80):
Your blood pressure reading
is ideal and
healthy.
More than 120 over 80 and less than 140 over 90
(
120/80
—
140/90):
You have a normal
blood pressure reading
but it
is a little higher than it should be, and you should try to lower it.
140 over 90 (140/90)
or higher
(over a number of weeks):
You may have high blood pressure (hypertension) and
should seek medical advice.
If in doubt about your readings, contact your medical team for advice.
