A state of persistent or overwhelming tiredness, reduced energy, or diminished capacity for physical or mental activity.
Fatigue can be physical, mental, or both. It may result from inadequate sleep, prolonged exertion, stress, illness, medications, nutritional deficiencies, or many other causes.
Unlike ordinary tiredness that improves with adequate rest, persistent or unexplained fatigue may indicate an underlying health problem and should be considered in the context of other symptoms.
QUICK FACT
Fatigue is not the same as simply feeling sleepy. A person can be fatigued while having difficulty sleeping or without actually feeling a strong need to sleep.
COMMONLY CONFUSED WITH
Sleepiness: Sleepiness is a tendency to fall asleep, whereas fatigue is primarily a lack of energy or ability to sustain activity.
SEE ALSO
