Work stress can kill you by raising the risk of heart disease by disrupting the body's internal systems, according to a study by University College London.

The findings come from a long-running study involving more than 10,000 British civil servants. The researchers measured stress among the civil servants by asking questions about their job demands, such as how much control they had at work, how often they took breaks and how pressed for time they were during the day.

Tarani Chandola, an epidemiologist at University College London, says: "This is the first large-scale population study looking at the effects of stress measured from everyday working life on heart disease.

"One of the problems is people have been sceptical whether work stress really affects a person biologically."

The team conducted seven surveys over a 12-year period and found chronically stressed workers, people determined to be under severe pressure in the first two of the surveys, had a 68% higher risk of developing heart disease.