The same levels of illness can lead different people - or the same person at different times - to either take a sickie or struggle into work. A team of researchers, led by Hanna Hultin from the Karolinska Institutet in Sweden, interviewed more than 400 people from six different workplaces within a few days of them taking Sick Leave. They found that problems in relationships with colleagues and superiors were more frequent in the days before people took sick leave and that people with a minor ailment were more likely to report sick when they expected that the following workday would be particularly stressful.