What is the Cause of Chronic Fatigue Syndrome?
What is the cause of Chronic Fatigue Syndrome? Although the cause of Chronic Fatigue Syndrome, or CFS, is not clearly understood, there is a great deal of ongoing research. It is possible that the syndrome results from multiple unrelated causes, including virus infection, stress, and toxins.
Infectious Diseases
Although there is some similarity to various acute or chronic infections, it now seems clear that CFS is not due to any single infectious disease. The Centers for Disease Control (CDC) conducted four-city surveillance and found no association with multiple disease-causing organisms called pathogens, including: Epstein-Barr virus, human retroviruses like HIV, human herpesvirus 6, enteroviruses, rubella, Candida albicans, bornaviruses, and Mycoplasma.
It remains unclear if infections may contribute to a subset of CFS cases. For example, recent research suggests that infection with Epstein-Barr virus, Ross River virus and Coxiella burnetti will lead to a condition that meets criteria for CFS in 12% of cases. Individuals who had severe acute illness were more likely to have persistent symptoms after six months and one year.
The Immune System
Another possibility is that the body’s immune system -- which is used to fight infection -- plays a role in developing CFS. Current research suggests that no immune disorders in CFS patients are on the scale traditionally associated with disease. Some investigators have observed findings of autoimmune disease. However, no associated tissue damage, opportunistic infections (as would be seen in someone whose immune system is not working), or increased risk for cancer have been observed among people with CFS, as would be expected.
Stress or viral infection may lead to a chronic expression of cytokines, a messenger of the immune system, leading to CFS. Unfortunately, no chronic cytokine secretion has been identified in the syndrome. Some investigators have seen improvement even despite continued high levels of circulating cytokines.
Finally, many individuals with CFS also have allergies, but this is not a universal finding.
The Central Nervous System
Part of the central nervous system, specifically what is called the Hypothalamic-Pituitary-Adrenal (HPA) axis, may play a role in the development of the disorder. Physical or emotional stress activates the HPA axis leading to increased cortisol and other hormones. These hormones influence the immune system and other body functions.
Studies have shown that CFS patients have lower average levels of cortisol than controls. Cortisol works to suppress inflammation and immune system activation. In a research trial, 70 CFS patients received either hydrocortisone to restore their cortisol levels to normal or placebo pills for 12 weeks. A placebo is a fake pill that contains an inactive substance which has no effect on the body (such as a sugar pill). It was found that this hormonal replacement was an ineffective treatment.
Nutritional Deficiency
There is no published scientific evidence that CFS is caused by a nutritional deficiency.
Source:
Chronic Fatigue Syndrome. Centers for Disease Control and Prevention, Department of Health and Human Services.
