Fatigue

Fatigue
Other names	Exhaustion, weariness, tiredness, lethargy, listlessness
Specialty	Primary care
Treatment	Avoid known stressors and unhealthy habits (drug use, excessive alcohol consumption, smoking), healthy diet, exercise regularly, medication, hydration, and vitamins

Fatigue describes a state of tiredness (which is not sleepiness), exhaustion^[1] or loss of energy.^[2][3]

Fatigue (in the medical sense) is sometimes associated with medical conditions including autoimmune disease, organ failure, chronic pain conditions, mood disorders, heart disease, infectious diseases, and post-infectious-disease states.^[4] However fatigue is complex and in up to a third of primary care cases no medical or psychiatric diagnosis is found.^[5][6][7]

Fatigue (in the general usage sense of normal tiredness) often follows prolonged physical or mental activity. Physical fatigue results from muscle fatigue brought about by intense physical activity.^[8][9][10] Mental fatigue results from prolonged periods of cognitive activity which impairs cognitive ability, can manifest as sleepiness, lethargy, or directed attention fatigue,^[11] and can also impair physical performance.^[12]

This article focuses on fatigue in the medical sense.