Fatigue

The state of feeling very tired, weary or sleepy resulting from insufficient sleep, prolonged mental or physical work, or extended periods of stress or anxiety (1) Fatigue is typically a normal, transient response to exertion, stress, boredom, or inadequate sleep but also may be unusually prolonged and indicative of disorder (e.g., chronic fatigue syndrome, anemia, hypothyroidism (2).

Source:

(1) Caldwell et al., Fatigue and its management in the workplace, 2019
(2) https://dictionary.apa.org/fatigue