It is mysterious but I think the evidence shows pretty well that it is NOT “characterized by fatigue.”

That is a misapprehension based on the name.

The main characteristics are actually a constellation of signs and symptoms ( not dissimilar to illnesses such as Parkinson’s or Alzheimer) which are not unique within themselves but form a distinct picture:

* Unrefreshing sleep; decreased slow-wave sleep
* Muscle Pain and Numbness
* Adverse reaction to abrupt stimuli
* A delayed worsening 24-48 post exertion (for tasks that would be considered normal or trival, e.g. tooth-brushing)
* Low Blood Volume or Orthostatic Intolerance
* Low NK Cell Function

In fact, most patients don’t even experience fatigue if they limit their activity to within a certain envelope of very simple tasks. The fatigue, or exhaustion, is in reaction to attempting tasks, such as climbing a stairway or making breakfast.

The name “Chronic Fatigue Syndrome” is for all intents and purposes a relic of the CDC’s investigation in of an outbreak of the illness in the 1980s. The prevailing name at the time was “Chronic Epstein Barr Syndrome” but once the association with Epstein Barr Virus was disproven in the mid-80s the new name chosen was the super nebulous “CFS.”

Thank you for reporting on this disease! We can only hope the biological samples gathered will be used as lemons to “make lemonade” in other important studies…

References:
1.) Carruthers BM, van de Sande MI, De Meirleir KL, Klimas NG, Broderick G, et al. Myalgic encephalomyelitis: International Consensus Criteria. J Intern Med. 2011 Oct;270(4):327-38. doi: 10.1111/j.1365-2796.2011.02428.x. Epub 2011 Aug 22. Review. PubMed PMID: 21777306; PubMed Central PMCID: PMC3427890.
2.) Brenu EW, Klimas NG et al. Immunological abnormalities as potential biomarkers in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. J Transl Med. 2011 May 28;9:81. PubMed PMID: 21619669; PubMed Central PMCID: PMC3120691.