Don L. Goldenberg, M.D., from Boston, states: “The fatigue in fibromyalgia (FM) is similar to that in…Chronic Fatigue Syndrome (CFS). Because there is an overlap in these two common syndromes, it may not be possible to separate…(them.)” An excerpt from another pamphlet calls CFS the “twin” of fibromyalgia. In fact, another name for CFS is myalgic encephaleomyelitis.
Often, sleep disturbances (insomnia, sleep apnea, narcolepsy) which cause daytime fatigue are mistaken for CFS or FM. But when a doctor is searching for the reason for insomnia or poor quality sleep, CFS and FMS should never be ruled out.
(Source: About.com’s CFS and FM guide.)