Are lyme disease and chronic fatigue syndrome related?

Similar symptoms: Lyme disease and chronic fatigue syndrome can have very similar symptoms. By definition, if one has chronic fatigue syndrome other causes of fatigue like lyme disease have been ruled out, so if one has lyme disease, by definition they do no have cfs. However, it is likely that many people who have been diagnosed with cfs actually have undiagnosed lyme disease. See comment for more:.