Table 1.

Key mechanisms underlying fibromyalgia advanced by ACR 1990 criteria.

Neural Mechanisms	Type of Mechanism
Peripheral	Mechanoreceptor input
	Referred pain
	Nociception
	Sympathetic nervous system
	Neuroinflammation
Spinal cord	Central sensitization
	Descending spinal cord control
Brain	Neurotransmitter changes
	Connectivity changes
	Neuroinflammation
Other mechanisms	Genetic
	Psychological
	Stress reactivity
	Social factors