Definition: Teacher Burnout is a phenomenon which affects many teachers either within a single school year or over the course of a number of years. Teaching is a very demanding job. Unlike many professions, success in teaching is hard to measure and varies by individual, by course, and by school. Further, teachers are often expected to fulfill many roles. Add in the effects of high stakes testing, and teachers have many pressures on them. This often leads to teachers "burning out." In the worst case, a teacher may leave the profession because of teacher burnout.