ME/CFS is a serious, debilitating illness characterized by a variety of symptoms including worsening post-exertional malaise (PEM), unrefreshing sleep, cognitive problems and orthostatic intolerance. Other symptoms of ME/CFS include pain, gastrointestinal problems (diarrhea, bloating, constipation), problems with body temperature regulation and a heightened risk of infection.
It is a very challenging illness to live with and many people are misdiagnosed or never diagnosed at all. This is because there are no lab tests for ME/CFS, and it can often take years before people with ME get a correct diagnosis. The medical community does not know what causes ME, but there are a number of theories.
Some of the most promising research is focusing on an area called the vagus nerve, which runs from the brain to the gut and controls numerous vital functions. One theory is that the microorganisms found in the digestive tract of people with ME/CFS are disrupting the vagus nerve, leading to a dysfunctional immune system.
Researchers are also investigating the possibility that ME/CFS is triggered by certain infections and may be an autoimmune disease. People with ME/CFS have been found to have a greater tendency to develop herpes B infections and recurrent Epstein-Barr virus infectious mononucleosis. Infections like this can lead to severe ME/CFS flares.
Because there is no laboratory test for ME/CFS, it must be diagnosed by a healthcare professional who will use history and physical examination, screening instruments and diagnostic tests to rule out other conditions. A GP or hospital consultant can help with this. ME/CFS can be difficult to diagnose because it is not well understood and can be mistaken for depression or anxiety, for example. However, PEM and orthostatic intolerance are distinctive features of ME/CFS that can be used to differentiate it from mood disorders. Treatment trials can also help – if treating an alternative condition completely eliminates the symptoms of ME/CFS, then ME/CFS is not the right diagnosis.