We all know someone who has had a heart attack or a stroke. That's inevitable, because more than half the population eventually has one of them, and around half of us eventually die from one. So should we accept that they are a normal part of life, and forget about them?

That's the normal attitude. 'We've got to die of something' is the usual reply when we doctors point out the risks that people take. That may be so, but surely not twenty years earlier than we might.

For that's the problem with the biggest killer in our midst. It's not cancer, or 'old age' or infectious diseases. It's high blood pressure. And the problem is that most of the people who have it don't know that they do. Because it usually causes no symptoms. No headaches, no dizziness, no feeling of being unwell, no loss of weight.

Most people with high blood pressure just carry on with their lives until it eventually hits them, out of the blue - with a heart attack or a stroke. The vast majority of strokes, and more than half of all heart attacks, happen in people who turn out to have high blood pressure.

That's why there's a new set of guidelines for doctors to seek out the people on their books with high blood pressure - and get them treated effectively as soon as possible. Because there are highly effective ways of lowering high blood pressure to normal levels, and they have been proved, time and again, to reduce the numbers of deaths from strokes and heart attacks. Caught in time, you can extend your life by 20 years or more.

The guidelines state that all adults should have their blood pressures measured routinely at least every five years until they are 80 years old. If they are at the high end of normal, the checks should be made every year. From this group upwards, to people with mild, moderate and severe high blood pressure, there should be strict rules about treatment.

Everyone with the least suspicion of high blood pressure should be taught how to lower it themselves. That means losing any excess weight sensibly - not with a crash diet, but with reasonable eating habits. They should start an exercise programme. Exercise lowers blood pressure and slows the resting heart rate, making the heart more efficient.

They should absolutely not smoke - at all. Smoking not only raises blood pressure, it also promotes clotting of the blood in the arteries and damages blood vessel walls, all actions that make heart attacks and strokes much more likely.

Alcohol is allowed, but only up to two drinks a day for women and three for men. Up to that level, it helps open up the circulation, making the blood flow more smoothly through the smaller arteries. Alcohol also improves blood cholesterol levels, so that fat is actually removed from artery walls.

But any more than this small amount of alcohol a day, and its bad effects quickly outdo the good. It becomes a poison, rather than a benefit, and can promote higher blood pressure. It is better to be teetotal than to drink too much if you have high blood pressure.

Then there is salt. Until recently the medical establishment has been divided about the effect that salty food has on blood pressure. Now opinion has swung against it. Big studies of populations strongly suggest that adding salt to cooking and at the table, and particularly eating preserved foods that are packed with salt, can push up the blood pressure into risky levels. Reducing a high salt intake has lowered heart attack and stroke rates in several communities under study.

Finally there are drugs to lower high blood pressure. There are several kinds, acting on different systems in the body. So there is always at least one that suits you. They are extremely effective at helping people to avoid strokes and heart attacks, particularly when taken with a small dose of aspirin to reduce heart attack risk, and, when it is needed, a drug to lower cholesterol levels, too.

In recent years, stroke rates have been diving, and heart attack rates are following on the downward slope. That is mainly due to healthier lifestyles - but a lot is also due to good medical care. So if you are over 40 and haven't had your blood pressure checked for a while, see your doctor. You could well save a life - your own.

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.