THE SCIENCE OF CHRONIC FATIGUE
There are several proposed explanations for chronic fatigue, such as neuroinflammation (inflammation in the brain), generalized immune system activation, intestinal dysbiosis (a disruption in the microbiome of the gut), hormonal changes, endothelial abnormalities (this refers to cells that line blood vessels, lymph vessels, and the heart), and dysfunction of the mitochondria (the energy-producing elements of the cells).
Reports of these abnormalities are documented in some who are affected.
How- ever, there are currently no specific biomarkers or other lab or imaging studies that confirm a diagnosis, as there is great variability among patients.
Furthermore, it is not clear that these abnormalities are the cause of the symptoms. Correlation does not necessarily imply causation.
There is research suggesting that inflammation and autonomic nervous system abnormalities are not causative of ME/CFS. First, if inflammation was a significant contributing cause, the most powerful blocker of inflammation, corticosteroids, would be expected to be effective.
However, they are not. Furthermore, inflammation does not change rapidly from moment to moment or from day to day, while the symptoms of ME/CFS typically are quite variable on a daily basis.
A study of biological markers in adolescents with chronic fatigue syndrome found large discrepancies between changes in these markers and the symptoms experienced.
Another study demonstrated that treatment with an autonomic nervous system blocker (clonidine) decreased autonomic nervous system activity and lowered inflammatory markers, yet had no effect on the symptoms.
If someone develops the symptoms of chronic fatigue, it is necessary to search for possible medical explanations, such as severe anemia, congestive heart failure, chronic lung disease, low thyroid, adrenal or testosterone hormone levels, advanced liver or kidney disease, insomnia and narcolepsy, advanced cancer, or side effects of certain medications.
The vast majority of those affected with ME/CFS do not have these underlying conditions. In fact, those with ME/CFS often have a much higher degree of fatigue and disability than do those with these medical conditions.
LYME DISEASE BECOMES CHRONIC
Acute Lyme disease is caused by infection with the Borrelia burgdorferi bacteria, transmitted to humans by the Ixodes (blacklegged) tick.
The acute infection can cause a red rash that can look like a bull's-eye or a round discoloration of the skin.
The rash occurs in about 70 percent of people with acute Lyme disease.
Acute Lyme disease can also cause fever, malaise, fatigue, body aches, and headache. In other words, it feels like the flu. But unlike the flu or Epstein-Barr, acute Lyme disease is caused by a bacterium, and a course of an oral antibiotic (usually doxycycline) cures the infection in almost all people.