Reviewed by Neal Uren, consultant cardiologist and Dr Dan Rutherford
Every adult over 40 should get their blood pressurechecked.
The heart is a pump designed to force blood through our body. Blood is
pumped from the heart through the arteries out to our muscles and organs.
Pumps work by generating pressure. Put simply, too much pressure puts
a strain on the arteries and on the heart itself. This can cause an artery
to rupture or the heart to fail under the strain - in the worst case
Blood pressure depends on a combination of two factors:
a.. how forcefully the heart pumps blood around the body
b.. how narrowed or relaxed your arteries are.
Hypertension occurs when blood is forced through the arteries at an
Around 10 million people in the UK have high blood pressure - that's
one in five of us.
What is normal blood pressure?
Blood pressure is measured using two numbers. An example of this could
be 'the blood pressure is 120 over 80', which is written as '120/80mmHg'.
a.. The first figure is the systolic blood pressure - the maximum
pressure in the arteries when the heart contracts (beats) and pushes blood
out into the body.
b.. The second figure is the diastolic blood pressure. This is the
minimum pressure in the arteries between beats when the heart relaxes to
fill with blood.
Because the height of a mercury column is used in blood pressure
gauges, standard blood pressure readings are always written as so many
'millimetres of mercury', which is abbreviated to 'mmHg'.
The systolic pressure is always listed first, then the diastolic
pressure. A typical normal blood pressure reading would be 120/80 mmHg.
What's classed as high?
There is a natural tendency for blood pressure to rise with age due to
the reduced elasticity of the arterial system. Age is therefore one of the
factors that needs to be taken into account in deciding whether a person's
blood pressure is too high.
In general terms, people with a systolic blood pressure consistently
above 160mmHg and/or a diastolic pressure over 100mmHg need treatment to
lower their blood pressure.
People with slightly lower blood pressures (140-159mmHg systolic or
90-99mmHg diastolic) may also need treatment if they have a high risk of
developing cardiovascular disease, eg stroke or angina (chest pains).
What are the symptoms?
One of the big problems with high blood pressure is that it hardly
ever causes symptoms.
This means it may go unnoticed until it causes one of its later
complications such as a stroke or heart attack.
Despite the popularity of such ideas, nosebleeds and ruddy complexions
are hardly ever caused by high blood pressure.
Severe hypertension can cause symptoms such as:
What complications are caused by high blood pressure?
a.. Atherosclerosis: narrowing of the arteries.
b.. Stroke: haemorrhage or blood clot in the brain.
c.. Aneurysm: dangerous expansion of the main artery either in the
chest or the abdomen, which becomes weakened and may rupture.
d.. Heart attack.
e.. Heart failure: reduced pumping ability.
f.. Kidney failure.
g.. Eye damage.
What causes hypertension?
For more than 90 per cent of people with high blood pressure, the
cause is unknown. This is called 'primary' or 'essential hypertension'.
In the remaining 10 per cent or so, there is an underlying cause. This
is called 'secondary hypertension'.
Some of the main causes for secondary hypertension are:
a.. chronic kidney diseases
b.. diseases in the arteries supplying the kidneys
c.. chronic alcohol abuse
d.. hormonal disturbances
e.. endocrine tumours.
What factors increase the risk of hypertension?
Anyone can suffer from high blood pressure, but certain factors can
seriously aggravate hypertension and increase the risk of complications:
a.. a tendency in the family to suffer hypertension
d.. diabetes Type 1 or Type 2
e.. kidney diseases
f.. high alcohol intake
g.. excessive salt intake
h.. lack of exercise
i.. certain medicines, such as steroids.
What can I do?
Every adult near or past middle age should 'know their numbers'- ie
your height, weight, blood pressure and cholesterol levels.
You should also have regular blood pressure tests if there is a family
tendency for hypertension. This way, treatment can be started before any
Change your lifestyle:
a.. stop smoking
b.. lose weight
c.. exercise regularly
d.. cut down on alcohol
e.. eat a varied diet
f.. reduce stress by trying different relaxation techniques, or by
avoiding stressful situations.
These changes will lower blood pressure - to reduce your risk of
developing the condition in the first place or to treat hypertension.
If your blood pressure requires medical treatment, you will probably
have to take medicine on a regular basis.
If so, never stop taking it without consulting your GP, even if you
feel fine. Hypertension can lead to serious complications if left untreated.
What can your doctor do?
a.. Pinpoint risk factors and help you change your lifestyle to
reduce blood pressure.
b.. Offer medication for the reduction of blood pressure and arrange
regular monitoring. Sometimes blood pressure control is not straightforward.
Many people require more than one drug on a regular basis to get their blood
pressure under good control.
c.. Your GP may wish to seek the advice of an expert in hypertension
if your blood pressure seems particularly difficult to control.
What are the treatment targets?
Diabetes considerably increases the risk of cardiovascular disease if
hypertension is also present, so the targets for blood pressure control in
diabetes are tighter.
For people who don't have diabetes, the treatment goals for blood
pressure for are:
a.. systolic pressure of less than 140mmHg
b.. diastolic pressure of less than 85mmHg.
For people with diabetes, the goals are:
a.. systolic pressure of less than 130mmHg
b.. diastolic pressure of less than 80mmHg.
Which medicines are used to treat hypertension?
a.. ACE inhibitors stop the production of a hormone called
angiotensin II that makes the blood vessels narrow. As a result, the vessels
expand, improving blood flow. Tension in the circulation is also lowered by
the kidneys filtering more fluid from the blood vessels into urine. This
also helps reduce blood pressure. If your blood pressure is not easily
controlled on simple medication, your doctor will probably use a medicine of
b.. Angiotensin-II receptor antagonists work in a similar way to ACE
inhibitors. But instead of stopping the production of angiotensin II, they
block its action. This allows the blood vessels to expand, improving blood
flow and reducing blood pressure.
c.. Beta-blockers block the effect of the hormone adrenaline and the
sympathetic nervous system on the body. This relaxes the heart so that it
beats more slowly, lowering the blood pressure.
d.. Alpha-blockers cause the blood vessels to relax and widen.
Combining them with beta-blockers has a greater effect on the resistance in
e.. Calcium-channel blockers reduce muscle tension in the arteries,
expanding them and creating more room for the blood flow. In addition, they
slightly relax the heart muscle so it beats more slowly, reducing blood
f.. Diuretics help the body get rid of excess salt and fluids via
the kidneys. In certain cases, they relax blood vessels, reducing the strain
on your circulation.
The following medicines are used less frequently.
a.. Indapamide is a mildly diuretic preparation that also relaxes
the peripheral arteries.
b.. Hydralazine relaxes the vascular walls in the peripheral
arteries thereby reducing the blood pressure.
c.. Methyldopa stimulates the alpha receptors in the brain that
relax the blood vessels, causing the blood pressure to drop.
d.. Moxonidine is another medicine that acts on receptors in the
involuntary part of the brain, causing blood pressure to decrease.
e.. Minoxidil relaxes the small arteries so that blood pressure
drops. It must be used in combination with other hypertension medicines.
In the long term
By treating hypertension well, complications can be avoided and
average life expectancy will remain almost normal.
Without treatment, life expectancy may well be reduced due to the risk
of developing complications such as heart failure or stroke.