http://www.nytimes.com/health/guides/disease/chronic-fatigue-syndrome/print.html
Chronic fatigue syndrome (CFS), sometimes called immune dysfunction syndrome or myalgic encephalomyelitis (in Europe), is not a new disorder. In the 19th century the term neurasthenia, or nervous exhaustion, was applied to symptoms resembling CFS. In the 1930s through the 1950s, outbreaks of disease marked by prolonged fatigue were reported in the United States and many other countries. Beginning in the early- to mid-1980s, interest in chronic fatigue syndrome was revived by reports in America and other countries of various outbreaks of long-term debilitating fatigue….
Fibromyalgia. Fibromyalgia causes prolonged fatigue and widespread muscle aches. It is the disease most often confused with CFS. The two conditions also commonly appear together. In fact, many experts believe fibromyalgia is simply another variant of chronic fatigue syndrome or they are different manifestations of the same disease. CFS patients experience severe fatigue, whereas fibromyalgia patients experience more pain. One hypothesis is that the connection between the two conditions may be found in central sensitization, which is thought to cause fibromyalgia and may also cause CFS…