Advice / Information About Blood Pressure
What is blood pressure?
Blood pressure is the pressure of blood in your arteries. The heart
pumps blood around your body through a network of arteries, by
contracting and then relaxing. When the heart contracts the blood is
forced through the arteries and your blood pressure goes up. This is
when your blood pressure is highest and is called the systolic
pressure. When your heart relaxes (between heart beats), your blood
pressure goes down. This is when the pressure is lowest and is known
as the diastolic pressure. These two pressures are written as
numbers, one over the other, like a fraction - eg.140/85 mmHg. The
top number is the systolic pressure and the bottom number is the
Why is blood pressure important?
Blood pressure is a valuable indicator of how at risk you are of
certain life threatening conditions. If your blood pressure is high
there is an increased risk of coronary heart disease and stroke.
Coronary heart disease is the number one cause of death in the UK,
and strokes are a major cause of long term disability and may
sometimes lead to death.
The following table shows how the likelihood of heart disease and
stroke increases with a higher blood pressure. The figures shown are
the two figures displayed when you take your blood pressure using a
blood pressure monitor.
BP Advice Body
What causes high blood pressure?
High blood pressure develops if the walls of the larger arteries
lose their natural elasticity and become rigid, and the smaller
blood vessels become narrow. Factors can be:
- Not doing enough physical activity
- Being overweight
- Too much salt in your diet
- Drinking too much alcohol
- Not eating at least five portions of fruit and vegetables each day
- Family history
- Occasionally some medications used to treat ulcers, arthritis or
depression may cause a rise in
blood pressure. In over nine out of every ten people there is no
definite cause of high blood
What are the symptoms of high blood pressure?
High blood pressure rarely makes people feel ill. It can cause
headaches in a very small number of people, but only if their blood
pressure is very high. Occasionally nose bleeds and eye problems may
be due to high blood pressure, although most people experience no
symptoms at all. The only way to know your blood pressure is to have
it measured, or to measure it yourself.
How is blood pressure measured?
Blood pressure is measured using a sphygmomanometer (pronounced
sfig-mo-man-ometer). This is usually a digital blood-pressure
monitor, which is made up of a box with a tube leading to a cuff.
The cuff is wrapped around your upper arm, and at the press of a
button will inflate to a certain level and then deflate. A sensor in
the cuff detects your pulse rate and changes the information into
blood pressure readings that appear on a display screen.
What should my blood pressure be?
Your target is to have a blood pressure below 140/85 mmHg. Readings
above this level are generally considered to be high. High blood
pressure is also known as hypertension. In contrast, low blood
pressure, or hypotension, is when the systolic blood pressure is
below 90-100mmHg and the diastolic below 60mmHg of mercury.
How is high blood pressure treated?
It is helpful to look at areas of your lifestyle that can cause high
blood pressure such as reducing your weight, eating at least five
portions of fruit and vegetables a day, cutting down on salt and
alcohol, stopping smoking, and being more physically active. For
tips on how to bring about these changes, visit www.bpassoc.org.uk.
If your blood pressure remains high in spite of these measures, you
may need to take medication recommended by your doctor.
White coat hypertension
Some people feel anxious and apprehensive when visiting the doctor,
and tend to have a higher blood pressure when the doctor measures
it. This is called "White coat hypertension" and may affect 10-20%
of patients. It can be diagnosed by patients measuring their own
blood pressure with an accurate monitor at home, or with a 24-hour
ambulatory blood pressure recording (which your doctor will
When is it best to measure blood pressure?
Blood pressure varies considerably from hour to hour throughout the
day, being highest in the morning and lowest at night. Blood
pressure tends to rise with age and also with anxiety and exercise,
so it is best to record your measurements when you are rested and
What other organisations can be contacted?
For more information on blood pressure and blood pressure monitors,
you can contact:
The Blood Pressure Association
60, Cranmer Terrace
You may also like to request a booklet called ‘Blood Pressure' from
the British Heart Foundation at www.bhf.org.uk.
What types of home blood pressure monitor are there?
If you have high blood pressure (hypertension), your doctor may
advise you to measure your own blood pressure using a home monitor.
The easiest type to use at home is the increasingly popular digital
electronic sphygmomanometer. This has an arm cuff, and an electronic
monitor that shows your reading. You can also get wrist-worn blood
pressure monitors, though these are considered to be less accurate.
However, their more compact size means that they are easily portable
for readings anytime, anywhere.
How do I use it?
Blood pressure monitors are generally quite easy to use. But it is a
good idea to get a health professional to show you how to use yours
correctly. This way you will avoid taking inaccurate readings, which
can cause unnecessary anxiety. You must remember that any single
reading does not provide an accurate picture of your blood pressure,
as your levels will vary naturally throughout the day. By taking
regular readings at the same time of day you will, over time, have a
good measure of your blood pressure level.
What are the benefits of measuring my own blood pressure?
Measuring your own blood pressure means that you can be more
actively involved in your own care. It can help you to manage your
drug treatment and your lifestyle. If you get ‘white coat
hypertension’, which is when your blood pressure is higher than
usual when measured in a clinical setting by a health professional,
you can benefit from taking your blood pressure yourself in the
relaxed and familiar surroundings of your home.
How do I choose a blood pressure monitor?
There are lots of monitors on the market. It is important to choose
one you are comfortable with. Electronic monitors start at around
£45. Ideally you should make sure that the model you choose has been
tested in the UK. The following monitors have been approved by the
British Hypertension Society (BHS), a independent body that is
widely considered a world authority concerning blood pressure. The
list is compiled from research papers and not from direct testing
but you may find it helpful as a guide.
BHS Blood pressure monitor list
Blood pressure risk factors
|Twice as likely
|Four times as likely
|Eight times as likely