The cause of fibromyalgia is unknown, but among the theories that have been advanced,
post traumatic-stress reaction [Liptan2016] appears most credible. In a nutshell, psychological
or physical trauma induces a self-perpetuating cycle of sympathetic nervous system arousal ('fight-or-flight')
that triggers and sustains prolonged abnormal muscle contraction. This prolonged elevated muscle tone in turn
depletes muscle-mitochondrial energy stores, resulting in increased levels of lactic acid being produced.
Lactic acid is responsible for the characteristic "burn" an athlete normally feels after a set of strength-training
exercises. But whereas in normal athletic training, the lactic acid dissipates after the workout, in the case
of fibromyalgia, the muscle tension never relaxes, and the lactic acid can never dissipate. Unfortunately, the
pain causes a reflex feedback cycle in which the neurological system is driven further into sympathetic arousal,
and muscle tension is further increased.
In addition to driving painful muscle contractions, the elevated sympathetic nervous system arousal also disrupts
the fibromyalgia-sufferer's sleep, resulting in a hypervigilance that has been characterized as "sleeping with one eye open."
This state prevents the patient from achieving the deep sleep state necessary for physical and mental repair.
The end result of this unrestful sleep is daytime fatigue and mental fog.
Other contributing factors may include
mitochondrial dysfunction.
Note that Dr. Weyrich has argued that mitochondrial dysfunction may be secondary to
overgrowth with yeasts and fungi, and [Shaw2008] has pointed out that elevated urinary levels
of tartaric acid and other markers of overgrowth with yeasts and fungi are associated with
fibromyalgia
[Dr. Weyrich: however, it is not clear that these findings are not better associated with a diagnosis of
chronic fatigue syndrome].