Work related stress can lead to very serious physical and mental/emotional problems. It tears someone from the inside first, and then the families and friends outside.
NOTE: I want to emphasize on the fact that I do not have this problem myself. I work with an incredible team that knows its limits, but still is very productive. I got the inspiration doing something totally unrelated. Having been close to people who have had work related stress problems and it nearly ruined their lives, I feel strongly about this issue.