HIGH BLOOD PRESSURE

What is it?

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).

Who gets it?

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.

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.

What are the symptoms?

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!

What tests will the Doctor want to 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.

What is the treatment?

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.