Individuals diagnosed with chronic fatigue syndrome (CFS) are considered challenging patients in many quarters, presenting with complaints of post-exertional malaise, constant flu-like symptoms, unrefreshing sleep, cognitive difficulties, and sometimes many other symptoms that don't seem to have any obvious pattern. Some patients appear ill; some patients do not appear ill. Diagnostic tests are usually unrevealing.

As would be expected, these seemingly non-specific complaints often result in a lack of a diagnosis, and, not infrequently an accusation of fakery. However, those in the trenches, both those treating CFS and those diagnosed with CFS, it is a very real thing. Many dislike the label “CFS,” and in other countries it is referred to as myalgic encephalomyelitis (ME). Actually, the 2003 Canadian Clinical Case Definition draws a distinction between CFS and ME: while both definitions require multiple symptoms in the setting of 6 months of unexplained fatigue to make the diagnosis, the ME criteria also consider the existence of post-exertional malaise.

Of interest, in the next couple of weeks the Institute of Medicine, working with the United States Department of Health and Human Services, will issue recommendations for new clinical diagnostic criteria and consider a new name(s) for what we now refer to as CFS or CFS/ME. The Institute of Medicine's Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome will hold a public release event for its consensus report on February 10th, 2015 from 11:00 am-12:00 pm EST at the Keck Center of the National Academies in Washington, D.C. (500 Fifth Street NW, Washington, DC). Interested individuals will be able to attend the public release event in person or virtually via webcast.

Monikers aside, there remains the question: What is CFS/ME? CFS/ME thought leaders see the conditions as an abnormal immune system response to a possibly wide variety of infectious or environmental triggers; this produces a chronic state of inflammation, autonomic dysfunction, impaired functioning, including neuroendocrine imbalances. Impacting about one million adults and children in the United States (by the CDC definition), the main criteria of CFS/ME include severe fatigue for 6 months or longer (3 months in children), malaise lasting days to weeks following even modest physical or mental exertion, unrefreshing sleep, and cognitive dysfunction (in some cases described as “brain fog”). Of course, there is often chronic pain, and not surprisingly an overlap in the minds of some with .

In addition, patients can suffer disturbing blood pressure and heart rate variations, and gastrointestinal dysfunction not unlike that experienced with irritable bowel syndrome, heat or cold intolerance, and persistent flulike symptoms. In addition to fibromyalgia, other common concomitantly diagnosed conditions include irritable bowel syndrome, joint hypermobility, interstitial cystitis, and migraine.

Unfortunately, there are no laboratory tests that can provide unequivocal assistance in making a diagnosis of CFS/ME. In the article "Chronic Fatigue Syndrome: The Current Status and Future Potentials of Emerging Biomarkers," published in June 2014, in the journal “Fatigue,” among the problems with the many published CFS/ME biomarker studies, the authors note, are small study sample sizes, the wide heterogeneity of the criteria used for patient selection leading to inconsistent findings, and the overlap of abnormalities found in CFS/ME patients with those of other conditions. More, technologies used in some of the studies, such as functional MRI and cytometry, are too expensive and impractical to be employed routinely in clinical settings.

Whether one is considering CFS, ME, or CFS/ME, the challenges seem daunting, whether it be in the diagnosis or the treatment of these conditions. These challenges seem beyond daunting when one stops to consider that we are still waiting, in 2015, for the right name for the CFS/ME phenomenon.

There is a long journey ahead of us, I think.