Lethargy is a state of tiredness, sleepiness, weariness,
fatigue, sluggishness or lack of energy. It can be accompanied by
depression, decreased motivation, or
apathy
Apathy is a lack of feeling, emotion, interest, or concern about something. It is a state of indifference, or the suppression of emotions such as concern, excitement, motivation, or passion. An apathetic individual has an absence of intere ...
. Lethargy can be a normal response to inadequate sleep, overexertion, overworking, stress, lack of exercise, improper nutrition,
boredom
In conventional usage, boredom, ennui, or tedium is an emotional and occasionally psychological state experienced when an individual is left without anything in particular to do, is listlessness and dissatisfaction arising from a lack of occup ...
, or a symptom of an underlying illness or a disorder. It may also be a side-effect of medication or caused by an interaction between medications or medication(s) and
alcohol. It may also be an
altered level of consciousness
An altered level of consciousness is any measure of arousal other than normal. Level of consciousness (LOC) is a measurement of a person's arousability and responsiveness to stimuli from the environment.
A mildly depressed level of consciousn ...
.
When part of a normal response, lethargy often resolves with rest, adequate sleep, decreased stress, physical exercise, and good nutrition. Lethargy's symptoms however can last days or even months,
so it can be a sign of a recent underlying illness or infection if it doesn't resolve normally.
See also
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Clinical depression
Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Intro ...
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Encephalitis lethargica
Encephalitis lethargica is an atypical form of encephalitis. Also known as "sleeping sickness" or "sleepy sickness" (distinct from tsetse fly-transmitted sleeping sickness), it was first described in 1917 by neurologist Constantin von Economo a ...
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Sleep apnea
Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many tim ...
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Sleep deprivation
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Somnolence
Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling asleep ...
References
External links
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Symptoms
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