It is believed by some researchers that repeated nerve stimulation causes people's brains to change that have fibromyalgia. These changes involve abnormal levels of chemicals inside of the brain that signal pain to increase. It is also believed to cause, the brain's pain receptors to overreact to the pain which causes the person to become more sensitive, to the pain signals.
Symptoms of fibromyalgia include:
Constant widespread pain
Sleep disturbance.
Lace of focus
Other painful conditions