Fibromyalgia - Causes

(Page 4)

Muscle Abnormalities

Some research found muscle abnormalities in fibromyalgia patients. These abnormalities 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 level of calcium in muscle cells. Calcium is an important component in the muscles' 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 saw overly thickened capillaries (tiny blood vessels) in the muscles of fibromyalgia patients. The abnormal capillaries could produce lower levels of compounds essential for muscle function, as well as reduce the flow of oxygen-rich blood to the muscles.
• Functional abnormalities: The pain and stress of the disease itself may harm muscle function.

Causes of Secondary Fibromyalgia

Secondary fibromyalgia has the characteristic symptoms of fibromyalgia but, unlike primary fibromyalgia, it has a specific cause. Possible causes include:

• Physical injury: In one study, for example, secondary fibromyalgia developed in over 20% of patients who had neck injuries. The symptoms are identical to those of primary fibromyalgia but are harder to treat. Another study reported a high rate of fibromyalgia in workers who had repetitive stress injuries, although it is not clear which condition came first.
• Ankylosing spondylitis (arthritis affecting the spine)
• Surgery
• Lyme disease

Click the icon to see an image of Lyme disease.

• Hepatitis C

Click the icon to see an image of hepatitis C.

• Endometriosis: According to a 2001 study, about 31% of women with endometriosis go on to develop fibromyalgia or chronic fatigue syndrome, a related illness.

Click the icon to see an image of endometriosis.

Review Date: 12/15/2006
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital