There’s data on this — there shouldn’t need to be, but there is — that suggests that when people come to work sick, they’re not as productive. Companies have problems with presenteeism — people physically on the job but not really paying attention to what they are doing — with lost workdays from psychological stress and illness, with high health care costs. Seven percent of people in one survey were hospitalized — hospitalized! — because of workplace stress; 50% had missed time at work because of stress. People are quitting their jobs because of stress. The business costs are enormous.
For someone like me with Type 1 diabetes and Grave's disease, workplace stress has a direct impact on health.
Tip of the hat to Duncan Stephen.