What do you know about diabetes? That it gives problems with sugar, and makes you very thirsty - and it can be cured by insulin?

That's about the sum total of most non-diabetics' knowledge of the disease. But it's a lot more than that - and everyone needs to be aware of it. For diabetes is promising to be the most serious health problem for middle aged adults in the next generation. So here are a few facts and fallacies about the disease.

It's such a serious illness you are bound to know when you have it. Wrong. Sure, children who develop it are quickly diagnosed from their raging thirst, sudden loss of weight. They are obviously ill. But adults may have undetected diabetes for years. They just feel a bit lethargic, disinclined to exercise much, and maybe a bit hungrier and thirstier than other people.

They may feel "normal" in themselves - as they don't know what normal is for other people. They only begin to realise how unwell they have been when they start treatment.

For every diabetic known to their doctors, there is another one we do not know about. Many adults blame their symptoms on being a bit lazy anyway. It's only when they go for a routine check-up - maybe at a well man or well woman clinic, or at an insurance medical - that they discover what's wrong. Some pregnant women do not know they are diabetic until the sugar shows up in their routine tests. Or they are only suspected of having diabetes when they deliver babies weighing nine pounds or more. (The babies grow larger when their mothers have a higher blood sugar level.)

Diabetes in pregnancy often disappears after the birth, but the mother must watch out for future signs of the disease, as she may develop it years later. People with diabetes need insulin injections. Wrong. Most children with diabetes do need insulin. But nine out of ten cases of diabetes start in adults, mostly because they are overweight. They need to lose weight, exercise regularly, eat healthily and generally improve their lifestyle. If they do, then most can manage without insulin, and even without tablets to control their blood sugar.

Once the diagnosis is made, as long as you take the treatment, you can consider yourself back to normal. Wrong. Not only do you have to keep checking the level of sugar (to be more correct, glucose) in your blood, you must also keep your blood pressure very much under control. That means visiting your diabetes clinic every month, for the rest of your life, without fail.

High blood pressure goes along with diabetes, and if you don't keep it within the normal range, you are inviting all sorts of complications in your circulation. That often means taking at least two different types of blood pressure-lowering drug, even though you don't have any symptoms of high blood pressure, like headaches or angina.

Why is all this so important? Because diabetes is now the commonest cause of leg amputations, blindness and the need for kidney dialysis and transplants in the developed world - including Britain. And strokes and heart attacks are far more common in diabetics of both sexes than in non-diabetics of the same age.

One reason for the poor outlook for people with diabetes may be found in the way the blood clots. Higher than normal sugar and fat levels in the blood of diabetics seem to promote clotting in the smallest blood vessels in the heart, brain, kidneys, eyes and legs - and this can cause all the complications.

One possible way to help may be for diabetics to start taking aspirin - just one aspirin a day. However, that has still to be proved - and aspirin, as everyone knows, has its possible downside (like irritation of the stomach and bleeding).

So I'm all for a proposed trial being set up by Professor Jill Belch, of Dundee University Medical School. She is looking for 1600 people in and around her area with diabetes, who have no current evidence of any problems with their circulation. Some will get aspirin, some an "anti-oxidant" such as vitamins E and C, some both, and some placebo. Following these groups over four years should give an idea of whether the treatments will be beneficial, of no value or even harmful.

Only by doing such trials can we hope to find out whether the treatments work. Only then can we start to prescribe them.

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