UNDERSTANDING HIGH BLOOD
PRESSURE
Introduction
Perhaps you have just been told that you have high blood pressure, and want
to know what this means - or perhaps you are simply interested in knowing more
about this condition. This booklet helps you understand what high blood
pressure is, and learn something about how it is treated.
What is high blood pressure?
The heart is a small but very powerful pump that beats steadily throughout
your life, pumping five litres (about 8 pints) of blood around the body every
minute. The smaller blood vessels through which the blood passes cause a
resistance to blood flow. The pumping of the heart against this resistance
creates the blood pressure necessary for the circulation of the blood. This
circulation is essential for nutrition of the major organs, such as the heart,
kidneys, liver and brain, providing the vital oxygen and nutrients necessary
for life. So, everyone needs to have a certain level of blood pressure to
maintain their circulation.
When the heart contracts, the highest pressure it produces is called the
systolic pressure; when it relaxes, the lowest pressure is called the diastolic
pressure. Both of these pressures are important in determining the risk of
heart attack and stroke, so both will be measured by your doctor. A normal
blood pressure in an adult, for instance, might be around 130/80 (often
described as 130 over 80) - this is shorthand for a systolic pressure of 130
and a diastolic pressure of 80.
Blood pressure is not constant, and tends to vary from minute to minute and
from day to day. It sometimes increases a lot with exercise, with excitement
and in emergencies, and is usually lower when you are at rest or asleep. This
is completely normal. If, though, the blood pressure is persistently high,
damage to the blood vessels, including hardening of the arteries
(atherosclerosis), can occur. Ultimately, this can lead to a heart attack
(myocardial infarction: MI) or a stroke (cerebrovascular accident: CVA).
Persistently high blood pressure, known to doctors as hypertension, is
common and will affect around 1 in every 7 adults. Blood pressure increases as
you grow older, and this may be one of the reasons why heart disease and
strokes are more common in older people.
High blood pressure causes no symptoms, so you will not know about it unless
the blood pressure is measured. Extremely fit and apparently healthy people can
sometimes have dangerously high blood pressure!
How is blood pressure measured?
Your doctor or practice nurse will measure your blood pressure using a cuff
which is wrapped around the upper arm, and attached to an instrument called a
sphygmomanometer. The pressure is detected using a stethoscope. Because blood
pressure varies, several readings are required to be sure of the result.
Measurements can be made with a machine at home which can sometimes provide
helpful information to doctors.
What causes high blood pressure?
In the vast majority of people with high blood pressure there is no single
clear-cut cause. This condition is called essential hypertension. A number of
factors combine to raise the blood pressure, of which heredity is most
important - high blood pressure tends to run in families. Contrary to popular
opinion, high blood pressure is not a disease of the nervous or highly strung,
nor is it caused by a stressful lifestyle.
In a very few people, there is a specific cause for high blood pressure, and
removal of the cause can produce a ,cure'. Your doctor will know when to look
out for the signs of these rare conditions. Continued research is important in
developing specific treatments.
Why do I need to know if I have high blood pressure?
If high blood pressure is untreated you are much more likely to suffer a
heart attack or stroke, and you could develop heart or kidney failure. This is
the reason that Life Assurance companies are so concerned about high blood
pressure. The good news is that the risks of high blood pressure can be greatly
reduced by treatment and the higher the blood pressure before treatment the
more worthwhile this is. In recent years, research has shown that it is worth
treating a systolic pressure above 160, or a diastolic pressure above 100. If
you have other medical problems, such as diabetes or angina, your doctor might
decide to treat a blood pressure slightly lower than 160/100.
How can I help myself?
First, if you smoke - stop! Smoking doubles your risk of heart disease and
trebles your chance of dying before reaching retirement. There are now many
aids to giving up smoking, such as nicotine chewing gum and skin patches, and
these do seem to help if you really want to give up.
Second, aim to keep your alcohol intake below the recommended limits of 3
units per day for men and 2 units per day for women (a unit is equivalent to a
half-pint of beer, a glass of wine, or a single measure of spirit). A small
amount of alcohol is probably fine for your health, but larger amounts can
increase the blood pressure, and may damage the liver and heart.
Third, avoid being overweight which can increase your blood pressure. It is
also bad for your joints and breathing. To reduce weight, it helps to avoid
foods high in saturated fats and calories, such as dairy products (butter,
cheese and full-fat milk), fried foods, eggs, cakes and biscuits, and fatty
meats. Instead you could try eating fish, white meat (such as chicken), and
plenty of fresh fruit and vegetables, as well as using skimmed milk, sunflower
oils and margarines. Keeping to a diet low in saturated fat and high in fibre
may also be good for your heart and blood vessels even if you are not
overweight.
Fourth, try to take regular exercise - overall, it reduces the blood
pressure and helps to keep weight down. Exercise need not be too strenuous and
should be built up slowly. If you are taking exercise three times each week, to
the point where you break sweat, with exercise lasting for about 30 minutes,
this should be enough. Walking, swimming, cycling and jogging are all
appropriate forms of exercise. If in doubt, ask your doctor.
Fifth, don't add salt to food at the table and avoid eating very salty
foods. Some people are very sensitive to the effects of salt which then can
increase blood pressure. For them, salt reduction can be particularly helpful.
Often food tastes a little different at first, but very soon the flavour
returns.
Alternatively, try using Lo-Salt, which contains potassium instead of sodium
- this may even help to reduce the blood pressure.
All of these measures are good for your heart and for your general health
and some of them will also lower your blood pressure. But even if the effect on
high blood pressure is not enough to avoid the need for tablets, they may help
reduce the dose or the number of tablets you have to take. It is worth
remembering that your chance of having a heart attack or stroke multiplies with
every extra risk factor (such as smoking or obesity) so you can gain major
benefits by taking sensible measures to help yourself.
What will the doctor do?
Unless your doctor knows you well, you will probably be asked some simple
questions about you and your immediate family. Your doctor may also examine you
and you may need to have blood and urine tests. Your doctor may also ask for an
electrocardiogram (known as an ECG). Unless the blood pressure is very high, it
will be checked on several separate occasions to confirm the level before any
treatment is started. It is important to tell your doctor about any painkillers
you take frequently, like aspirin. Oral contraceptives and nasal decongestants
can also increase blood pressure in some people, so tell your doctor about
these too.
Measurements of blood pressure at home are sometimes helpful, particularly
if it appears that your blood pressure goes up when it is measured by a doctor
or nurse. This is the so-called white-coat effect. It is important to let your
doctor know about any chest pain and it is vital to mention any numbness or
weakness in your arms or legs or if you suffer loss of vision or speech,
however brief.
Why should I take the treatment?
First, it is important to know that nowadays there are many effective
treatments for high blood pressure. Treatment can usually be found to suit you.
The most commonly used types of drugs are diuretics, beta-blockers, ACE
inhibitors and calcium antagonists.
Generally, side effects only occur in a small proportion of patients taking
each drug, are mild and usually clear up rapidly. Although uncommon, some of
the drugs may cause impotence in men, particularly the thiazides and
beta-blockers. Let your doctor know if this, or other possible side-effects,
develop after starting treatment. For women, always let your doctor know if you
become pregnant or intend to do so, because some drugs are more suitable than
others during pregnancy and your doctor will want to keep a closer eye on you.
No two people are exactly the same which is why all treatments have to be
individually chosen. Remember, there are a large number of drugs available to
treat high blood pressure - so if the first does not suit you, see your doctor
who can change your treatment. Some people need more drugs than others so it
may take a few visits to get things just right. It is quite common to feel a
little dizzy with the first few doses of a treatment, but this usually clears
up. Your body may take some time to adjust to the new lower level of blood
pressure, but in the long run it will prove well worthwhile. Never stop your
tablets without talking to your doctor first.
Apart from those rare exceptions when a specific reason is found, there is
no cure for high blood pressure. Treatment lowers the blood pressure, but the
blood pressure will rise again if the treatment is stopped - although not
always immediately. The commonest reason for the treatment not working is that
the tablets aren't being taken at all. So remember to take them as directed by
your doctor. Also, never forget the benefits of treatment - you may not feel
any different, but you will be much less likely to suffer a stroke or heart
attack. So, keep yourself healthy and commit yourself to taking the tablets
regularly.
Is there anything else I should know?
After some time on the treatment you should hardly notice it, apart from
having to remember to take your tablets and visiting your doctor regularly to
check that the treatment is working. Once the blood pressure has been reduced
you should not feel ill and treatment should not stop you enjoying your usual
work, leisure pursuits or sex life. There is also no reason why you should not
continue to drive. It is worth trying to take regular exercise and avoid being
overweight, smoking, or drinking too much alcohol. Lastly, if you have high
blood pressure and need to attend hospital for some other reason, it is always
useful to take your tablets with you and mention to the doctors that you are
being treated for high blood pressure.
It helps to keep a list of all your medicines.
Summary
- High blood pressure is common - one in seven people have it and are at a
higher risk of suffering a heart attack or stroke
- Most people with high blood pressure feel perfectly well - the only way to
find out if you have high blood pressure is to have it checked.
- High blood pressure cannot usually be cured - but it can be treated
successfully.
- Lifestyle modifications, such as reducing weight and alcohol intake, are
helpful - and can sometimes reduce the need for tablets. Stopping smoking will
dramatically reduce your chance of having a heart attack or stroke.
- Treatment can usually be found that will keep your blood pressure within
normal limits - without side effects. You should continue to lead a normal
active life.
- With treatment - which is usually necessary for the rest of your life - the
risk of a stroke or heart attack is greatly reduced.
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