fatique

Fatique, often spelled fatigue, refers to a subjective sensation of tiredness, lack of energy, or exhaustion that is not proportional to recent activity and that can impair daily functioning. It can be temporary or persistent and may affect physical energy, mental performance, or motivation. Fatique is distinct from sleepiness and from muscle weakness.

Most fatigue arises from a combination of lifestyle factors and medical conditions. It is commonly described as acute when it lasts hours to days and chronic when it persists for weeks or months. Clinically, fatigue can be physical (reduced ability to sustain effort) or mental (diminished concentration and motivation).

Common causes include inadequate sleep, poor sleep quality, stress, poor nutrition, and inactivity. Medical causes span anemia, thyroid disorders, diabetes, infections, chronic diseases (such as cancer or heart or lung disease), liver or kidney disease, and pain syndromes. Medications (antihistamines, sedatives, antidepressants) and substances (alcohol, caffeine withdrawal) can contribute.

Evaluation typically begins with a medical history and physical examination, followed by targeted laboratory tests (for example, complete blood count, thyroid function, iron studies, glucose, and liver/kidney tests). Red flags such as weight loss, fever, night sweats, neurological symptoms, or persistent weakness warrant further workup.

Management focuses on identifying and treating underlying conditions while supporting energy and well-being. Approaches include improving sleep hygiene, regular graded physical activity, balanced nutrition, stress management, and, when appropriate, cognitive behavioral therapy and symptom-directed therapies. In persistent cases such as chronic fatigue syndrome, care emphasizes education, pacing, and multidisciplinary support.