Speaking of Japan, it's worth mentioning that the Japanese did indeed coin a term in the 1980s after the death of several high-ranking business executives who had previously showed no outward signs of illness.
<a href="http://www.apmforum.com/columns/boye51.htm"><i>Karoshi</i> (Kah-roe-she) - Death from overwork</a>
Your teacher talked about the girl who stressed herself to do the best work she could do. This does not seem like a bad thing, merely the desire to feel pride in a job VERY well done.
Contrast this with the really bad stress, the kind where you go to work for a company at the expense of EVERYTHING else, your family, your mental health, your physical health - that stress is the bona fide killer I've seen first hand.
Think of a job where the workplace politics and dynamics are so seething and cancerous that workmates are shunned for refusing to slowly kill themselves. That's stress you can't control, far beyond a simple individual desire to do good work.