Fibromyalgia - Causes

Immune Abnormalities

Fibromyalgia has some symptoms that resemble a number of rheumatic illnesses, including rheumatoid arthritis and lupus (systemic lupus erythematosus). These are autoimmune diseases in which a defective immune system mistakenly attacks the body's own healthy tissue, producing inflammation and damage. The pain in fibromyalgia, however, does not appear to be due to autoimmune factors, and there is little evidence to support a role for an inflammatory response in fibromyalgia.

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Psychological and Social Effects

Although not primary causes, psychological and social factors may contribute to fibromyalgia in three ways:

They could make individuals susceptible to fibromyalgia.
They may play some role in triggering the onset of the condition.
They may perpetuate, or be responsible for, the condition.

Studies have reported a greater incidence of severe experiences of victimization from emotional and physical abuse in patients with fibromyalgia than in the general population. Most often the abuse originated from family or partners. This suggests that post-traumatic stress disorder (PTSD) or chronic stress may play a strong role in the development of fibromyalgia in some patients. PTSD is an anxiety disorder that is a reaction to a specific traumatic event. Symptoms of this condition, which can occur for years after the traumatic event, include emotional withdrawal, hopelessness, irritability, mood swings, sleep problems, inability to concentrate, and an excessive startle response to noise. There is some evidence that PTSD actually results in changes in the brain, possibly from long-term overexposure to stress hormones.

Muscle Abnormalities

Some research has detected muscle defects in fibromyalgia patients, which can be classified as follows:

Biochemical abnormalities. For example, one study reported that fibromyalgia patients had lower levels of the muscle-cell chemicals phosphocreatine and adenosine triphosphate (ATP). Such chemicals regulate the ebb and flow of calcium in muscle cells, an important component in their ability to contract and relax. If ATP levels are low, calcium is not "pushed back" into the cells and the muscle remains contracted.
Structural and blood flow abnormalities. Some researchers have observed overly thickened capillaries (tiny blood vessels) in the muscles of fibromyalgia patients, which could produce lower levels of certain compounds essential for muscle function as well as reduce the flow of oxygen-rich blood to these tissues.
Functional abnormalities. The pain and stress of the disease itself may impair muscle function.