According to studies,

[…]stress costs US businesses up to $300 billion dollars in lost productivity each year. In the wake of such statistics, there is beginning to be a larger discussion about burnout, which is essentially when stress and pressure (often in the workplace) have become so great that overall quality of life and quality of work become negatively impacted.

Check out this great infographic, taken from The Simple Dollar, that explains about some of the common warning signs of burnout and how to prevent it from taking a solid hold on you.

Source: TheSimpleDollar.com