Redigerer Kronisk utmattelsessyndrom (avsnitt)

== Patofysiologi ==
Mekanismene og patogenesen av kronisk utmattelsessyndrom er ukjent.<ref name="CDCBasic"/> Forskningsstudier har undersøkt og laget hypoteser om de mulige biomedisinske og epidemiologiske egenskapene ved sykdommen, inkludert oksidativt stress, genetisk disposisjon,<ref name="pmid17853290">{{cite journal |author=Sanders P, Korf J |title=Neuroaetiology of chronic fatigue syndrome: An overview |journal=World J Biol Psychiatry |volume= 9|issue= 3|pages=1–7 |year=2007 |pmid=17853290 |doi=10.1080/15622970701310971 |url=http://www.informaworld.com/openurl?genre=article&doi=10.1080/15622970701310971&magic=pubmed |unused_data=|1B69BA326FFE69C3F0A8F227DF8201D0}}</ref> virale eller bakterielle infeksjoner, abnormaliteter i hypothalamus-hypofyse-binyre-aksen, dysfunksjoner i immunsystemet samt psykologiske og psykososiale faktorer. Selv om det er uklart hvilke faktorer som kan være årsaker til eller konsekvenser av CFS, har ulike modeller blitt foreslått.<ref name="pmid11388124">{{cite journal |author=Patarca-Montero R, Antoni M, Fletcher MA, Klimas NG |title=Cytokine and other immunologic markers in chronic fatigue syndrome and their relation to neuropsychological factors |journal=Appl Neuropsychol |volume=8 |issue=1 |pages=51–64 |year=2001 |pmid=11388124 |doi= 10.1207/S15324826AN0801_7|url=}}</ref><ref name="pmid17561686">{{cite journal |author=Kuratsune H |title=[Overview of chronic fatigue syndrome focusing on prevalence and diagnostic criteria] |language=japansk |journal=Nippon Rinsho |volume=65 |issue=6 |pages=983–90 |year=2007 |month=June |pmid=17561686 |doi= |url=}}</ref><ref name="pmid9859853">{{cite journal |author=Vercoulen JH, Swanink CM, Galama JM, ''et al'' |title=The persistence of fatigue in chronic fatigue syndrome and multiple sclerosis: development of a model |url=https://archive.org/details/sim_journal-of-psychosomatic-research_1998-12_45_6/page/507 |journal=J Psychosom Res |volume=45 |issue=6 |pages=507–17 |year=1998 |pmid=9859853| doi = 10.1016/S0022-3999(98)00023-3 }}</ref> 

En studie fra 2009 antydet en sammenheng mellom retroviruset xenotropic murine leukemi virus-related virus (XMRV) og kronisk utmattelsessyndrom i USA.<ref name="pmid19815723">{{Cite journal | author= Lombardi VC, Ruscetti FW, Das Gupta J, Pfost MA, Hagen KS, Peterson DL, Ruscetti SK, Bagni RK, Petrow-Sadowski C, Gold B, Dean M, Silverman RH, Mikovits JA | year= 2009 | title= Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome | journal= Science | volume= 326 | issue= 5952 | pages= 585–9 | doi= 10.1126/science.1179052 | pmid=19815723}}</ref> Fire oppfølgingsstudier i Storbritannia, USA og Nederland fant derimot ingen slik sammenheng.<ref name="PLoSOne">{{cite journal |author=Erlwein, O, ''et al.'' |title=Failure to Detect the Novel Retrovirus XMRV in Chronic Fatigue Syndrome |journal=PLoS ONE |volume= |issue= |pages= |year=2010 |pmid=20066031 |pmc= |doi=10.1371/journal.pone.0008519 |url=http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0008519}}</ref><ref>{{cite journal |author=Harriet C T Groom, Virginie C Boucherit, Kerry Makinson, Edward Randal, Sarah Baptista, Suzanne Hagan, John W Gow, Frank M Mattes, Judith Breuer, Jonathan R Kerr, Jonathan P Stoye, Kate N Bishop |title=Absence of xenotropic murine leukaemia virus-related virus in UK patients with chronic fatigue syndrome |journal=Retrovirology |volume= |issue= |year=2010 |pmid=20156349 |doi=10.1186/1742-4690-7-10 |url=http://www.retrovirology.com/content/7/1/10/abstract}}</ref><ref name="van_Kuppeveld">{{cite journal |author=van Kuppeveld FJ, Jong AS, Lanke KH, ''et al.'' |title=Prevalence of xenotropic murine leukaemia virus-related virus in patients with chronic fatigue syndrome in the Netherlands: retrospective analysis of samples from an established cohort |journal=BMJ |volume=340 |issue= |pages=c1018 |year=2010 |pmid=20185493 |pmc=2829122 |doi= |url=http://www.bmj.com/cgi/content/full/340/feb25_1/c1018}}</ref><ref name="cdc_xmrv">{{Kilde artikkel 
 | forfatter1  = William M Switzer
 | forfatter2  = Hongwei Jia
 | forfatter3  = Oliver Hohn
 | forfatter4  = HaoQiang Zheng
 | forfatter5  = Shaohua Tang
 | forfatter6  = Anupama Shankar
 | forfatter7  = Norbert Bannert
 | forfatter8  = Graham Simmons
 | forfatter9  = R Michael Hendry
 | forfatter10 = Virginia R Falkenberg
 | forfatter11 = William C Reeves
 | forfatter12 = Walid Heneine
 | tittel = Absence of evidence of Xenotropic Murine Leukemia Virus-related virus infection in persons with Chronic Fatigue Syndrome and healthy controls in the United States
 | publikasjon = Retrovirology
 | år = 2010
 | bind = 7
 | hefte = 57
 | sider = 
 | doi = 10.1186/1742-4690-7-57
 | url = https://retrovirology.biomedcentral.com/articles/10.1186/1742-4690-7-57
}}</ref>