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Tiredness/fatigue in adults - Background information
What is it?
- Tiredness/fatigue
- Chronic tiredness/fatigue has been defined as tiredness/fatigue lasting 6 months or longer [Ruffin and Cohen, 1994], but there is no consensus.
- Chronic fatigue syndrome (CFS)/myalgic encephalomyelitis or encephalopathy (ME)
- There is no universal definition of CFS/ME but diagnostic criteria are recommended by the National Institute for Health and Clinical Excellence (NICE), which also recommends that a diagnosis should be made (in adults) when symptoms have persisted for 4 months, after exclusion of other possible diagnoses [National Collaborating Centre for Primary Care, 2007].
- Using older US criteria for CFS/ME (that differ from the current NICE criteria), it is reported that between a fifth and a third of people with unexplained tiredness/fatigue lasting 6 months meet the criteria for CFS/ME [Wessely et al, 1997; Darbishire et al, 2003].
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