These physical symptoms can have very serious effects on your health. According to the American Psychological Association, if allowed to progress, burnout can result in depression, anxiety, and physical illness. Drugs or alcohol are often a problem. After an extended period of time burnout can cause physical and mental breakdowns, which include suicide, stroke, or heart attack ("The Road to Burnout." American Psychological Association HelpCenter ).
Before burnout gets to the point of causing severe mental and health problems, it will affect how you do your job. Absenteeism and lateness are two of the effects. Doing the bare minimum, in other words "mailing it in" is another. It's ironic. You work your tail off to avoid losing your job. You burn yourself out and you're unable to do your job well, if it all. Then you lose your job. The cost of burnout is high, both to workers and to employers. So, it's time to start exploring ways to keep burnout from progressing.