It has been shown by psychologists that even the good things in our lives cause us stress and can possibly lead to illness.

Just think of all the things that can happen in a single lifetime. Going to school, making friends, taking exams, moving house, leaving school, getting a job, getting married, having children, the list is endless. Every one of these events can cause stress, which can eventually lead to ill health.

In 1967, two doctors, Holmes and Rahe, were the first to link life events to stress. By looking at a large number of patients they found that certain life events could be associated with stress and poor health. The ones that seemed to have the most profound effect on health were the ones that caused some kind of 'change' in the person's life.

Even positive events such as getting married were associated with poor health. Holmes and Rahe suggested that because the event took up so much of our energy, there was less energy available for things like the physical defence against illness.

This idea led Holmes and Rahe to come up with their Social Readjustment Rating Scale (SRRS). They got people to rate events on a scale of 0 -100 with 0 being not at all stressful and 100 being extremely stressful.

They calculated an average for each life event in their scale and ended up with a list of 43 items with 'death of a spouse' being given a score of 100, 'marriage' a score of 53 and 'Christmas' a score of 12.

To measure your own stress levels all you had to do was tick any event that had happened to you in the previous 12 months and add up your total score. The higher your score, the more likely you are to suffer from stress related illnesses at some point.

Obviously there are some problems with this scale. It is far too simplistic. Some people love Christmas, while some people hate it so their own feelings of stress would possibly be different. The end of a relationship may cause grief and despair for one person but happiness to a person who has been in a bad relationship.

Because of these individual differences in a persons perception of the event it is hard to say exactly how much stress each person is under during these events.