Most people will experience stressful or challenging periods in their careers, but when that stress becomes long-term, it can be physically and emotionally draining. This phenomenon is known as burnout.

A 2015 survey by Deloitte found that more than three-quarters of U.S. adults (77%) have experienced burnout in their current role, while half of millennials have resigned from a position due to feeling burned out.

But burnout is not an official diagnosis, said Jeremy Jamieson, an associate professor of psychology at the University of Rochester in New York. “It's a more normative experience of being overwhelmed for long periods of time rather than a psychiatric disorder,” he told Live Science.

In 2019, burnout was included in the 11th revision of the International Classification of Diseases (ICD-11), according to the World Health Organization (WHO), and was classified as an “occupational phenomenon” as opposed to a medical condition. The ICD-11 definition states that burnout is the result of “chronic workplace stress” and can lead to energy depletion or exhaustion, increased mental distance from one’s job, feelings of negativism or cynicism related to one's job and reduced professional efficacy.

According to the charity Mental Health UK, common signs of burnout include feeling tired or drained for an extended period of time, a feeling of helplessness, being trapped and/or defeated, excessive and debilitating self-doubt, and procrastination.

What causes burnout?

However, Jamieson said that a scenario liable to cause burnout in one person is not necessarily going to trigger the same response in someone else.

“Psychologically, the primary processes [involved in burnout] seem to be cognitive appraisals,” he said. “When we're presented with demands — a work assignment or job interview, for example — we appraise whether we possess the resources to meet those demands. If we repeatedly appraise that our resources cannot meet demands, burnout can occur.”