There are several theories about the causes of fibromyalgia, from hormonal disturbances to stress to genetics. While there is no clear consensus about what causes fibromyalgia, most researchers believe fibromyalgia results not from a single event but from a combination of many physical and emotional stressors.
Other Theories About Causes of Fibromyalgia
Some have speculated that lower levels of a brain neurotransmitter called serotonin leads to lowered pain thresholds or an increased sensitivity to pain. Serotonin is associated with a calming, anxiety-reducing reaction. The lowered pain thresholds in fibromyalgia patients may be caused by the reduced effectiveness of the body's natural endorphin painkillers and the increased presence of a chemical called "substance P." Substance P amplifies pain signals.
There have been some studies that link fibromyalgia to sudden trauma to the brain and spinal cord. Keep in mind, though, theories about what causes fibromyalgia are merely speculative.
Who Gets Fibromyalgia?
Fibromyalgia is far more common in women than in men. Some interesting studies show that women have approximately seven times less serotonin in the brain. That may explain why fibromyalgia syndrome, or FMS, is more common in women.
Another theory states that fibromyalgia is caused by biochemical changes in the body and may be related to hormonal changes or menopause. In addition, some (but not all) people with fibromyalgia have low levels of human growth hormone, which may contribute to the muscle pain.
Does Stress Cause Fibromyalgia?
Some researchers theorize that stress or poor physical conditioning are factors in the cause of fibromyalgia. Another theory suggests that muscle "microtrauma" (very slight damage) leads to an ongoing cycle of pain and fatigue. This mechanism, like all the others, is still unproven for fibromyalgia.
Do Insomnia or Sleep Disorders Cause Fibromyalgia?
Most people with fibromyalgia experience insomnia or non-restorative sleep -- sleep that is light and not refreshing. Disordered sleep might lead to lower levels of serotonin, which results in increased pain sensitivity. Researchers have created a lower pain threshold in women by depriving them of sleep, possibly simulating fibromyalgia.
Is Depression Linked to Fibromyalgia?
Some scientists used to believe that because fibromyalgia was accompanied by low-grade depression, there may be a link between the two illnesses. Today, mental health issues are no longer thought to cause fibromyalgia. However, chronic pain can cause feelings of anxiety and depression, which may worsen fibromyalgia symptoms.
Is Fibromyalgia Hereditary?
Like other rheumatic diseases, fibromyalgia could be the result of a genetic tendency that's passed from mother to daughter. Some researchers believe that a person's genes may regulate the way his or her body processes painful stimuli. These scientists theorize that people with fibromyalgia may have a gene or genes that cause them to react intensely to stimuli that most people would not perceive as painful. Several genes have been found to occur more often in people with fibromyalgia.
It's thought that when a person with this genetic tendency is exposed to certain emotional or physical stressors -- such as a traumatic crisis or a serious illness -- there is a change in the body's response to stress. This change can result in a higher sensitivity of the entire body to pain.