I would venture to say it never is. I worked in a toxic environment for five years, and it literally made me ill.

My hair started falling out in big handfuls and I had constant digestive problems. I went to a series of doctors and ended up with an endocrinologist who said my thyroid was overactive and might need to be irradiated to stop the problems. Then at my next appointment, it was under-active. It didn't make sense.

I had already been looking for a new job, and I changed jobs after that second appointment. A month later, all of my problems had gone away. It turned out all the havoc in my body was just due to stress.

They could have quadrupled my pay and it still wouldn't have been worth the effects on my health.