{{short description|State of tiredness, weariness, fatigue, or lack of energy}} {{distinguish|Fatigue}} {{For|the 1990s band|Lethargy (band)}}
'''Lethargy''' is a state of physical or mental weariness, [[fatigue (medical)|fatigue]], sluggishness, or lack of energy. It can be accompanied by [[Depression (mood)|depression]], decreased motivation, or [[apathy]], but can also present with having a desire, but not the energy to initiate or perform tasks.<ref>{{Cite web |title=Lethargy (Concept Id: C0023380) - MedGen - NCBI |url=https://www.ncbi.nlm.nih.gov/medgen/7310 |access-date=2026-05-18 |website=www.ncbi.nlm.nih.gov |language=en}}</ref> Lethargy can be a normal response to inadequate sleep, overexertion, overworking, stress, lack of exercise, improper nutrition, drug abuse, [[boredom]], or a symptom of an underlying illness or disorder. It may also be a side effect of medication or caused by an interaction between medications and [[alcoholic drink|alcohol]]. It may also be an [[altered level of consciousness]].<ref>{{Citation |last=Tindall |first=Suzie C. |title=Level of Consciousness |date=1990 |url=https://www.ncbi.nlm.nih.gov/books/NBK380/ |work=Clinical Methods: The History, Physical, and Laboratory Examinations |editor-last=Walker |editor-first=H. Kenneth |edition=3rd |place=Boston |publisher=Butterworths |isbn=978-0-409-90077-4 |pmid=21250221 |access-date=2022-03-26 |editor2-last=Hall |editor2-first=W. Dallas |editor3-last=Hurst |editor3-first=J. Willis}}</ref>
When part of a normal response, lethargy often resolves with rest, adequate sleep, decreased stress, physical exercise, and good nutrition.<ref>Hall J. E., Guyton A. C. (2006): Textbook of medical physiology, 11th edition. Elsevier Saunders, St. Louis, Mo, {{ISBN|0-7216-0240-1}}.</ref> Its symptoms, however, can last days or even months,<ref>{{Cite web |title=Chronic fatigue syndrome - Symptoms and causes |url=https://www.mayoclinic.org/diseases-conditions/chronic-fatigue-syndrome/symptoms-causes/syc-20360490 |access-date=2022-03-26 |website=Mayo Clinic |language=en}}</ref> so it can be a sign of a recent underlying illness or infection if it does not resolve normally.
== See also == * [[Clinical depression]] * [[Disorders of diminished motivation]] * [[Encephalitis lethargica]] * [[Sleep apnea]] * [[Sleep deprivation]] * [[Somnolence]] * [[Altered level of consciousness]] == References == {{Reflist}}
== External links == * {{wiktionary-inline}}
[[Category:Symptoms]]
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