Lethargy is a state of tiredness, sleepiness, weariness,
fatigue
Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
, 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, drug abuse,
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 occu ...
, 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
Alcohol most commonly refers to:
* Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom
* Alcohol (drug), an intoxicant found in alcoholic drinks
Alcohol may also refer to:
Chemicals
* Ethanol, one of sev ...
. 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. Introdu ...
*
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 times ...
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Sleep deprivation
Sleep deprivation, also known as sleep insufficiency or sleeplessness, is the condition of not having adequate duration and/or quality of sleep to support decent alertness, performance, and health. It can be either chronic or acute and may vary ...
*
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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