fatigue
Meaning of fatigue: Persistent exhaustion that does not fully resolve with rest, fatigue can arise from physical illness, psychological strain, or simply insufficient sleep.
Definition of fatigue
Fatigue is a persistent sense of tiredness or lack of energy that does not fully improve with rest, and that can affect the ability to carry out ordinary physical or mental tasks. It differs from simple sleepiness in that a person may feel exhausted even after adequate sleep, and it often includes a sense of reduced motivation or mental fog alongside physical weariness.
Fatigue can be acute, developing over a short period and resolving once its cause is addressed, or chronic, persisting for weeks or months. Acute fatigue commonly follows illness, exertion, or poor sleep, while chronic fatigue is more often associated with an underlying medical condition, a mental health condition, or ongoing treatment such as chemotherapy.
Because fatigue is a nonspecific symptom that can accompany conditions ranging from anemia and thyroid disorders to depression and chronic infection, evaluating its underlying cause typically involves considering the pattern, duration, and accompanying symptoms rather than treating fatigue as a diagnosis in itself.
Used in a sentence
The patient reported several weeks of fatigue that had not improved with rest.
Good to know
Fatigue that persists despite adequate rest and sleep is treated differently from ordinary tiredness, since a persistent pattern more often points toward an underlying medical or psychological cause.