Stress is a major problem in Western culture. The British government estimated that stress cost the UK economy over '7 billion ($14 billion) in 2001. With up to 80% of all industrial accidents due to stress, it's rapidly becoming a major problem that both industry and health care companies want to tackle and reduce.

When you get stressed a hormone known as Adrenocorticotrophic or ACTH is released in to your bloodstream. This triggers the fight or flight mechanism, which translates to your heart rate speeding up as blood is pumped more rapidly around the body.
Short term, this is fine as it works its way out of your system. Long term though and it becomes a problem as it stays in your system wearing you down. Eventually it will damage your immune system and possibly even cause a heart attack.

Why?

The human heart is designed to run steadily at a certain rate with occasional bursts to a higher rate. When you get stressed, your heart rate increases and the more stressed you are during the day the more your heart beat stays at the higher rate.

Let's compare this to a car to give you a more visual idea of what we are talking about. Imagine you are in your car in a low (or first gear). Without your foot on the gas pedal, it ticks over nicely. That's equivalent to your regular resting heart beat.

Now, put your foot flat to the floor and listen to the noise of the engine. That's equivalent to your racing heart beat.

What do you think would happen to your engine if you drove everywhere with it racing and making that noise? How far would you get before the engine exploded into pieces?

The analogy shows you what you are doing to your heart when you are continually stressed.

It is not coincidence that otherwise healthy people who exercise, eat well and don't drink or smoke suddenly have heart attacksit's from the build up of stress in their lives.

In 2002 the British Medical Journal published the results of an experiment where they followed hundreds of people for up to ten years and monitored their lives. What they discovered was that people who felt they were over-whelmed by their work or who did mundane day to day activities with no chance of development or advancement were almost three times as likely to develop heart disease as those who didn't have these stresses.

They also discovered that these people suffering from stress were two to three times more likely to have a life ending heart attack.

And that's simply from stress.