Fatigue (medical)

(Redirected fromFatigue (physical))This article is about the medical term. For other uses, seeFatigue.Not to be confused withmuscle weakness.Fatigue

ICD-10R53

ICD-9780.7

DiseasesDB30079

MedlinePlus003088

MeSHD005221

Fatigue(also calledexhaustion,tiredness,languidness,languor,lassitude, andlistlessness) is a subjective feeling of tiredness which is distinct fromweakness, and has a gradual onset. Unlike weakness, fatigue can be alleviated by periods ofrest. Fatigue can have physical or mental causes. Physical fatigue is the transient inability of amuscleto maintain optimal physical performance, and is made more severe by intensephysical exercise.[1][2][3]Mental fatigue is a transient decrease in maximal cognitive performance resulting from prolonged periods of cognitive activity. It can manifest assomnolence,lethargy, ordirected attention fatigue.[4]Medically, fatigue is anon-specific symptom, which means that it has many possible causes. Fatigue is considered asymptom, rather than asignbecause it is a subjective feeling reported by the patient, rather than an objective one that can be observed by others. Fatigue and 'feelings of fatigue' are often confused.[5]Contents[hide] 1Classification 1.1Physical fatigue 1.2Mental fatigue 2Comparison with sleepiness 3Causes 3.1Chronic fatigue 4Diagnosis 5See also 6References 7Further reading 8External linksClassification[edit]Physical fatigue[edit]Main article:Muscle fatigue

"Avoid fatigue - Eat alunchthat packs a punch"Physical fatigue, or muscle fatigue, is the temporary physical inability of a muscle to perform optimally. The onset of muscle fatigue during physical activity is gradual, and depends upon an individual's level of physical fitness, and also upon other factors, such assleep deprivationand overall health. It can be reversed by rest.[6]Physical fatigue can be caused by a lack of energy in the muscle, by a decrease of the efficiency of the neuromuscular junction or by a reduction of the drive originating from the central nervous system.[7]The central component of fatigue is triggered by an increase of the level ofserotoninin the central nervous system.[8]During motor activity, serotonin released in synapses that contactmotoneuronspromotes muscle contraction.[9]During high level of motor activity, the amount ofserotoninreleased increases and a spillover occurs.Serotoninbinds to extrasynaptic receptors located on theaxoninitial segment ofmotoneuronswith the result thatnerve impulseinitiation and thereby muscle contraction are inhibited.[10]Muscle strength testing can be used to determine the presence of aneuromuscular disease, but cannot determine itsetiology. Additional testing, such aselectromyography, can provide diagnostic information, but information gained from muscle strength testing alone is not enough to diagnose most neuromuscular disorders.[11]Musculoskeletalstructures may have co-evolved with their corresponding brain structures in a way that allows them to adapt to environmental conditions (e.g.proprioception).[12][13]People withmultiple sclerosisexperience a form of overwhelming lassitude or tiredness that can occur at any time of the day, for any duration, and that does not necessarily recur in a recognizable pattern for any given patient, referred to as "neurological fatigue".[14][15]Mental fatigue[edit]Mental fatigue is a temporary inability to maintain optimal cognitive performance. The onset of mental fatigue during any cognitive activity is gradual, and depends upon an individual's cognitive ability, and also upon other factors, such as sleep deprivation and overall health. Mental fatigue has also been shown to decrease physical performance.[4]It can manifest as somnolence, lethargy, ordirected attention fatigue. Decreased attention is known asego depletionand occurs when the limited 'self-regulatory capacity' is depleted.[16]It may also be described as a more or less decreasedlevel of consciousness.[17]In any case, this can be dangerous when performing tasks that require constant concentration, such as operating large vehicles. For instance, a person who is sufficiently somnolent may experiencemicrosleep. However, objective cognitive testing can be used to differentiate the neurocognitive deficits of brain disease from those attributable to tiredness.[citation needed]Theperceptionof mental fatigue is believed to be modulated by the brain'sreticular activating system(RAS).[citation needed]

Comparison with sleepiness[edit]Fatigue is generally considered a more long-term condition than sleepiness (somnolence).[18]Although sleepiness can be asymptomof medical issues, it usually results from lack of restful sleep, or a lack ofstimulation.[19]Chronic fatigue, on the other hand, is a symptom of a greater medical problem in most cases. It manifests in mental or physical weariness and inability to complete tasks at normal performance.[20]Both are often used interchangeably and even categorized under the description of 'being tired.'Causes[edit]Fatigue is a normal result ofworking, mentalstress, overstimulation and understimulation,jet lagor activerecreation,depression, and alsoboredom,diseaseandlack of sleep. It may also have chemical causes, such aspoisoningormineralorvitamindeficiencies. Chronic blood loss frequently results in fatigue, as do other conditions that causeanemia. Fatigue is different from drowsiness, where a patient feels that sleep is required. Fatigue is a normal response to physical exertion or stress, but can also be a sign of a physical disorder.Temporary fatigue is likely to be a minorillnesslike thecommon coldas one part of thesickness behaviorresponse that happens when theimmune systemfights aninfection.Chronic fatigue[edit]Prolonged fatigueis a self-reported, persistent (constant) fatigue lasting at least one month.Chronic fatigueis a self-reported fatigue lasting at least six consecutive months. Chronic fatigue may be either persistent or relapsing.[21]Chronic fatigue is a symptom of many diseases and conditions. Some major categories of diseases that feature fatigue include: Autoimmune diseasessuch asceliac disease,lupus,multiple sclerosis,myasthenia gravis, andspondyloarthropathy Blood disorderssuch asanemiaandhemochromatosis Cancer, in which case it is calledcancer fatigue Chronic fatigue syndrome(CFS)[22] Drug abuseincludingalcohol abuse[22] Depressionand other mental disorders that featuredepressed mood Eating disorders, which can produce fatigue due to inadequate nutrition Endocrine diseaseslikediabetes mellitusandhypothyroidism Fibromyalgia Gulf War syndrome Heart disease HIV Inborn errors of metabolismsuch asfructose malabsorption.[23][24] Infectious diseasessuch asinfectious mononucleosis. Irritable bowel syndrome Leukemiaorlymphoma Liver failure Lyme disease Neurological disorderssuch asnarcolepsy,Parkinson's diseaseandpost-concussion syndrome Physical traumaand otherpain-causing conditions, such asarthritis Sleep deprivationorsleep disorders Spring fever Stroke Uremia, which is caused by kidney diseaseFatigue may also be a side effect of certainmedications(e.g.,lithium salts,ciprofloxacin);beta blockers, which can induceexercise intolerance; and many cancer treatments, particularlychemotherapyandradiotherapy.Diagnosis[edit]

Minordark circles, in addition to a hint ofeye bags, a combination mainly suggestive of minorsleep deprivation.One study concluded about 50% of people who have fatigue receive a diagnosis that could explain the fatigue after a year with the condition. In those people who have a possible diagnosis, musculoskeletal (19.4%) and psychological problems (16.5%) are the most common. Definitive physical conditions were only found in 8.2%.[25]If a person with fatigue decides to seek medical advice, the overall goal is to identify and rule out any treatable conditions. This is done by considering the person'smedical history, any other symptoms that are present, and evaluating of the qualities of the fatigue itself. The affected person may be able to identify patterns to the fatigue, such as being more tired at certain times of day, whether fatigue increases throughout the day, and whether fatigue is reduced after taking a nap.Because disruptedsleepis a significant contributor to fatigue, a diagnostic evaluation considers the quality of sleep, theemotionalstate of the person, sleep pattern, and stress level. The amount of sleep, the hours that are set aside for sleep, and the number of times that a person awakens during the night are important. Asleep studymay be ordered to rule out asleep disorder.Depressionand other psychological conditions can produce fatigue, so people who report fatigue are routinely screened for these conditions, along withdrug abuse, poor diet, and lack ofphysical exercise, which paradoxically increases fatigue.Basicmedical testsmay be performed to rule out common causes of fatigue. These includeblood teststo check for infection oranaemia, aurinalysisto look for signs ofliver diseaseordiabetes mellitus, and other tests to check for kidney and liver function, such as acomprehensive metabolic panel.[26]Other tests may be chosen depending on the patient's social history, such as anHIV testorpregnancy test.See also[edit] Cancer-related fatigue Combat stress reaction Fatigue (safety) Gaucher's Disease Heat illness Malaise Microsleep Presenteeism Sleep-deprived drivingReferences[edit]1. Jump up^Gandevia SC (1992). "Some central and peripheral factors affecting human motoneuronal output in neuromuscular fatigue".Sports medicine (Auckland, N.Z.)13(2): 938.doi:10.2165/00007256-199213020-00004.PMID1561512.2. Jump up^Hagberg M (1981). "Muscular endurance and surface electromyogram in isometric and dynamic exercise".Journal of Applied Physiology51(1): 17.PMID7263402.3. Jump up^Hawley JA, Reilly T (1997). "Fatigue revisited".Journal of sports sciences15(3): 2456.doi:10.1080/026404197367245.PMID9232549.4. ^Jump up to:abMarcora SM, Staiano W, Manning V (January 2009). "Mental fatigue impairs physical performance in humans".Journal of Applied Physiology106(3): 857864.doi:10.1152/japplphysiol.91324.2008.PMID19131473.5. Jump up^Berrios GE (1990)."Feelings of fatigue and psychopathology: a conceptual history".Compr Psychiatry31(2): 14051.doi:10.1016/0010-440X(90)90018-N.PMID2178863.6. Jump up^"Weakness and fatigue". Healthwise Inc. Retrieved2 January2013.7. Jump up^Gandevia SC (2001). "Spinal and supraspinal factors in human muscle fatigue".Physiol. Rev.81(4): 172589.PMID11581501.8. Jump up^Davis JM, Alderson NL, Welsh RS (2000)."Serotonin and central nervous system fatigue: nutritional considerations"(PDF).Am. J. Clin. Nutr.72(2 Suppl): 573S8S.PMID10919962.9. Jump up^Perrier JF, Delgado-Lezama R (2005). "Synaptic release of serotonin induced by stimulation of the raphe nucleus promotes plateau potentials in spinal motoneurons of the adult turtle".J Neurosci.25(35): 79939.doi:10.1523/JNEUROSCI.1957-05.2005.PMID16135756.10. Jump up^Cotel F, Exley R, Cragg SJ, Perrier JF (2013)."Serotonin spillover onto the axon initial segment of motoneurons induces central fatigue by inhibiting action potential initiation".Proc Natl Acad Sci U S A110(12): 47749.doi:10.1073/pnas.1216150110.PMC3607056.PMID23487756.11. Jump up^Enoka RM, Duchateau J (1 January 2008)."Muscle fatigue: what, why and how it influences muscle function".The Journal of Physiology586(1): 1123.doi:10.1113/jphysiol.2007.139477.PMC2375565.PMID17702815.12. Jump up^Edelman, Gerald Maurice (1989).The remembered present: a biological theory of consciousness. New York: Basic Books.ISBN0-465-06910-X.13. Jump up^Kelso, J. A. Scott (1995).Dynamic patterns: the self-organization of brain and behavior. Cambridge, Mass: MIT Press.ISBN0-262-61131-7.14. Jump up^Comi G, Leocani L, Rossi P, Colombo B (March 2001). "Physiopathology and treatment of fatigue in multiple sclerosis".J. Neurol.248(3): 1749.doi:10.1007/s004150170222.PMID11355149.15. Jump up^Mills RJ, Young CA, Pallant JF, Tennant A (2010)."Development of a patient reported outcome scale for fatigue in multiple sclerosis: The Neurological Fatigue Index (NFI-MS)".Health Qual Life Outcomes8: 22.doi:10.1186/1477-7525-8-22.PMC2834659.PMID20152031.16. Jump up^Baumeister, R. F. (2002). Ego Depletion and Self-Control Failure: An Energy Model of the Self's Executive Function. Self and Identity, 1, 129-136.17. Jump up^AJ Giannini Fatigue,Chronic. In RB Taylor Difficult Diagnosis--2. Philadelphia, WB Saunders Co.,1992,pg 156.ISBN 0-7216-3481-818. Jump up^Shen J, Barbera J, Shapiro CM (2006). "Distinguishing sleepiness and fatigue: focus on definition and measurement".Sleep Med Rev10(1): 6376.doi:10.1016/j.smrv.2005.05.004.PMID16376590.19. Jump up^Hoddes E, Zarcone V, Smythe H, Phillips R, Dement WC (1973). "Quantification of sleepiness: a new approach".Psychophysiology10(4): 4316.doi:10.1111/j.1469-8986.1973.tb00801.x.PMID4719486.20. Jump up^Mayou R (1999)."Chronic fatigue and its syndromes".BMJ318(7176): 133A.doi:10.1136/bmj.318.7176.133a.PMC1114599.PMID9880310.21. Jump up^Fukuda K, Straus SE, Hickie I, Sharpe MC, Dobbins JG, Komaroff A (15 December 1994)."The chronic fatigue syndrome: a comprehensive approach to its definition and study. International Chronic Fatigue Syndrome Study Group.".Ann Intern Med121(12): 9539.doi:10.1059/0003-4819-121-12-199412150-00009.PMID7978722.22. ^Jump up to:abAvellaneda Fernndez A, Prez Martn A, Izquierdo Martnez M, Arruti Bustillo M, Barbado Hernndez FJ, de la Cruz Labrado J, Daz-Delgado Peas R, Gutirrez Rivas E, Palacn Delgado C, Rivera Redondo J, Ramn Gimnez JR (2009)."Chronic fatigue syndrome: aetiology, diagnosis and treatment".BMC Psychiatry. 9 Suppl 1: S1.doi:10.1186/1471-244X-9-S1-S1.PMC2766938.PMID19857242.23. Jump up^Whitehead WE, Palsson O, Jones KR (2002). "Systematic review of the comorbidity of irritable bowel syndrome with other disorders: What are the causes and implications?".Gastroenterology122(4): 11401156.doi:10.1053/gast.2002.32392.PMID11910364.24. Jump up^Gibson PR, Newnham E, Barrett JS, Shepherd SJ, Muir JG (2006). "Review article: Fructose malabsorption and the bigger picture".Alimentary Pharmacology & Therapeutics25(4): 34963.doi:10.1111/j.1365-2036.2006.03186.x.PMID17217453.25. Jump up^Nijrolder I, van der Windt D, de Vries H, van der Horst H (November 2009)."Diagnoses during follow-up of patients presenting with fatigue in primary care".CMAJ181(10): 6837.doi:10.1503/cmaj.090647.PMC2774363.PMID19858240.26. Jump up^EMedicine Health."Fatigue Exams and tests"2010-01-25.