The causes ofchronic fatigue syndrome(ME/CFS) are unclear.
These factors may include:
Not everyone with chronic fatigue syndrome has all of these factors.
Research is trying to identify the genes that could be responsible.
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Some has focused on the genes involved in thehypothalamic-pituitary-adrenal(HPA) axisand the sympathetic nervous system.
The HPA axis controls your sleep, response to stress, and depression.
An infectious trigger is also suspected because many ME/CFS cases start suddenly after a flu-like condition.
Other infections that have been suspected and studied include HHV-6, Lyme disease, andenterovirus.
However, none of these infections has been shown tocauseME/CFS.
However, some evidence seems to run counter to the viral cause theory.
Some ME/CFS patients show evidence of decreased ATP production.
Among the most common areallergiesand an overactive immune system.
The immune system produces many chemicals that are collectively calledcytokines.
These act on immune cells to regulate their behavior in many ways.
T-cells are active in both producing and calming the immune response.
Some people with this syndrome show abnormal T-cell activation, while others do not.
Natural killer (NK) cells are immune system cells that help the body fight infection.
Research is ongoing to find the specific mechanism that could lead to impairment of these cells.
These may be influenced by genetics, infection, or stress.
Each bodily function, thought, and emotion is linked to the operations of specific neurotransmitters.
When the activity of a particular one is too high or too low, things can start to malfunction.
Some people with ME/CFS have abnormal levels of certain important neurotransmitters (serotoninanddopamine).
It could also be that there is enough present but the receptors for them are not working properly.
Researchers are working to explain the role these abnormalities play in chronic fatigue syndrome.
Stress Hormone Deficiencies
The level of the stress hormone cortisol tends to be low in ME/CFS patients.
Disturbed Circadian Rhythms
Yourcircadian clock(part of the HPA axis) regulates your sleep-wake cycle.
While it is sometimes linked to clinical depression,chronic fatigue syndrome is a distinct condition.
These can include solvents, pesticides, or heavy metals.
As research continues, there may be a breakthrough in identifying the cause and risk factors for ME/CFS.
Centers for Disease Control and Prevention.Myalgic encephalomyelitis/chronic fatigue syndrome: Possible causes.
2016;6:e730.
doi:10.1038/tp.2015.208
Tomas C, Newton J, Watson S.A review of hypothalamic-pituitary-adrenal axis function in chronic fatigue syndrome.ISRN Neurosci.
2018;13(2):e0192817.
2017;114(34):E7150-E7158.
2015;16:35. doi:10.1186/s12865-015-0101-4
Glassford JA.The Neuroinflammatory Etiopathology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).
Centers for Disease Control and Prevention.
2012;79(3):403-7. doi:10.1016/j.mehy.2012.06.007
Chronic fatigue syndrome.
Chu L, Valencia IJ, Garvert DW, Montoya JG.Onset Patterns and Course of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.
