Fibromyalgia (FMS)
What causes it?
No one knows what causes fibromyalgia. One hypothesis is that when a person who is genetically predisposed to the syndrome comes in contact with some environmental trigger, symptoms develop. Most patients attribute the onset of fibromyalgia to a stressor, such as an acute injury, an illness with fever, surgery or long-term psychosocial stress (sometimes childhood trauma).
Researchers have made some progress in determining what is happening in the body that might cause some of the symptoms people experience. Most agree that the central nervous system in people with fibromyalgia is not functioning properly and that components of the body’s stress response are responsible for symptoms.
- Sensory processing: Disturbances are probably general and not pain-specific. People with fibromyalgia often experience great sensitivity not just to pain but to loud noises, bright lights, odors, drugs, temperature changes and chemicals.
- Substance P: People with fibromyalgia have approximately threefold higher concentrations in their spinal fluid of this chemical that amplifies pain signals than healthy controls.
- Serotonin: This brain chemical is believed to modulate pain signals and has been found to be low or processed poorly in people with fibromyalgia
- HPA axis: Several abnormalities in the hypothalamic-pituitary-adrenal axis (the brain and hormone interactions that regulate virtually all physiologic activities, including the stress response) have been noted.
- Growth hormone: Some people with fibromyalgia have low levels of growth hormone, which may contribute to postexertional muscle pain.
- Psychological and behavioral factors: Psychological disorders are no longer believed to cause fibromyalgia. However, the anxiety and depression brought about by chronic pain and fatigue can make fibromyalgia symptoms worse, creating a cycle of pain, fatigue, anxiety, maladaptive behaviors leading to more pain, etc.
