Stress and Sickness?

At what point does stress pass into sickness?

I've been contemplating this around the Toirdhealbheach Beaucail household as both myself and The Ravishing Mrs. TB have been dragging around our traditional October sicknesses. For myself at least, it seems not only related to any potential bug that has been generously brought home to me by Na Clann; there is an abiding sense of inability to sleep for longer than 3 hours at a time, a general sense of exhaustion, and now this headache which gnaws at my face during the day and at night.

Yes, I know there is something going around - but I'm also conscious of a more general sense of work beginning to overshadow and overpower all other aspects of my life. An analysis of what I still need to accomplish reveals over 100 separate tasks by the end of the year, plus the day to day items that continue to add up. When does all this knowing - and not enough time or resources to accomplish it all - pass over into physical effects?

I'm not sure - but this cannot be maintained forever.