| Fibromyalgia is sometimes categorized as primary or | | | | to treat. Another study reported a high incidence of |
| secondary. In primary fibromyalgia, also known as | | | | fibromyalgia in workers with repetitive stress injuries, |
| idiopathic fibromyalgia, the causes are not known | | | | although it is not clear which condition caused the |
| whereas in secondary fibromyalgia the causes can be | | | | other. |
| identified. Primary fibromyalgia is the more common | | | | - Ankylosing spondylitis. Ankylosing spondylitis is a |
| form. | | | | form of chronic inflammation of the spine and the |
| Many experts believe that primary fibromyalgia is not | | | | sacroiliac joints located in the low back where the |
| a disease but rather a chronic pain condition brought | | | | sacrum meets the iliac bones. |
| on by a dysfunctional biologic response to stress. | | | | - Surgery. Trauma, particularly in the upper spinal |
| Individuals are thought to be more susceptible to | | | | region, may trigger the development of fibromyalgia. |
| stress because of traumatic personal histories, | | | | - Lyme disease. According to one study, between 10- |
| genetic factors, or both. Physical injuries, emotional | | | | and 25-percent of patients with Lyme disease |
| trauma, or viral infections, such as Epstein-Barr, may | | | | subsequently developed fibromyalgia, which did not |
| act as triggers for the onset of the disorder. | | | | respond to the standard Lyme treatment consisting |
| In secondary fibromyalgia, a specific cause can be | | | | of antibiotics. |
| identified. Possible causes of secondary fibromyalgia | | | | - Hepatitis C. Hepatitis C may prove to be a trigger |
| include: | | | | for some cases of fibromyalgia. |
| - Physical injury. As an example, secondary | | | | - Endometriosis. Approximately 30 percent of women |
| fibromyalgia developed in over 20 percent of patients | | | | with the painful condition known as endometriosis go |
| who had neck injuries. The symptoms are identical to | | | | on to develop fibromyalgia or chronic fatigue |
| those of primary fibromyalgia but are more difficult | | | | syndrome, a related illness. |