Burnout has become a general word for being worn out. Its original definition is narrower, tied specifically to work, and built from three components that were meant to appear together.
The three components
The construct as it is measured has three parts. The first is exhaustion, meaning depleted emotional and physical resources that rest does not readily restore.
The second is a growing mental distance from the job, expressed as cynicism about the work or detachment from the people it involves.
The third is a reduced sense of professional efficacy, in which a person judges their own performance as poor regardless of how it appears to others.
It was framed as occupational
The condition was described in an occupational context and classified as a workplace phenomenon rather than a medical diagnosis, which has consequences for how it is used.
Classifying it as occupational places the source in the conditions of the job. The intended reading is that the situation produced the state, not that the individual was insufficiently resilient.
Which is why the original research programme focused on workload, control, reward, community, fairness and values as the factors that generate it.
The mismatch model
The influential explanation frames burnout as a chronic mismatch between a person and their job across those areas rather than as simple overwork.
Excessive workload is only one route. Low control over how work is done, effort that goes unrecognised, unfair processes and a conflict between personal and organisational values all contribute.
This explains cases that puzzle observers, where someone working reasonable hours burns out while a colleague working longer ones does not.
Overlap with depression complicates it
Exhaustion, detachment and a low view of one's own capability also describe depression, and the two states share considerable ground in measurement.
The proposed distinction is that burnout remains tied to a specific domain while depression generalises across life, though that boundary is not clean in practice.
The practical consequence is that someone assuming they have burnout may have a treatable condition that a change of job will not resolve.
Individual remedies address a structural cause
Most workplace responses are aimed at the individual, offering resilience training, mindfulness sessions or wellbeing applications alongside unchanged working conditions.
These can help someone cope, but the mismatch model predicts limited effect, because the driver sits in the organisation of the work rather than in the person doing it.
Where exhaustion persists across settings, disturbs sleep or is accompanied by hopelessness, assessment by a clinician is the appropriate step rather than further self-management.