Even if you eat well, go to the gym every day and have muscular biceps, you're still at risk of heart disease. But there's still a prevention factor in living healthily.

Millions of people suffer from the early stages of heart disease without even realising it, says Dr Kriengkrai Heng-russamee, chief of the Chest Disease Institute's Cardiology Department.

"Many people come here only after they suffer a heart attack," he says.

We often hear about regular users of the gym and even professional athletes falling ill or dying suddenly. Sportsman Ekachai "Yor Yong" Nopchin-da, Kriengkrai says, knew the risks but still smoked and didn't get enough sleep. His heart was working too hard.

Improper diet and risky life-style choices are the major causes of heart disease. Having an annual health check-up is essential because your blood-sugar level and blood pressure are key indicators.

A lot of people don't get regular check-ups, complains Kriengkrai, and not because they can't afford it. "They simply ignore the importance."

In 2004 heart attacks killed 426 of every million people in Thailand, and this year Kriengkrai's institute has treated 3,000 people for heart ailments, up from 600 in 1998.

Heart disease has four stages, the first one all but impossible to detect. In Stage 2 the symptoms are barely perceptible. Only in Stage 3 do most people realise they have a problem, when chest pains and feelings of indigestion show up. The last stage requires hospitalisation.

In the early stages, recovery is possible with better diet and exercise. By the third stage your chances drop to 50-50, by the final stage to 15 per cent.

Kriengkrai doesn't want the number of victims to keep increasing. He advises everyone to watch their diet, exercise regularly but not obsessively, and have regular check-ups - especially men over 35, women who have reached menopause and people whose families have a history of the disease.

Life in the balance

>> You need balance in terms of food, exercise and work.

The chance of becoming stricken with heart disease increases if you get exhausted easily.

>> Smoke, work too much, sleep too little, or over-exercise.