Fibromyalgia (new Latin, fibro-, fibrous tissues, Gk. myo-, muscle, Gk. algos-, pain, meaning muscle and connective tissue pain; also referred to as FM or FMS) is a medical disorder characterized by chronic widespread pain and allodynia, a heightened and painful response to pressure. It is an example of a diagnosis of exclusion. Fibromyalgia symptoms are not restricted to pain, leading to the use of the alternative term fibromyalgia syndrome for the condition. Other symptoms include debilitating fatigue, sleep disturbance, and joint stiffness. Some patients may also report difficulty with swallowing, bowel and bladder abnormalities, numbness and tingling, and cognitive dysfunction. Fibromyalgia is frequently comorbid with psychiatric conditions such as depression and anxiety and stress-related disorders such as posttraumatic stress disorder. Not all people with fibromyalgia experience all associated symptoms. Fibromyalgia is estimated to affect 2–4% of the population, with a female to male incidence ratio of approximately 9:1.
The brains of fibromyalgia patients show structural and behavioral differences from those of healthy individuals, but it is unclear whether the brain anomalies cause fibromyalgia symptoms or are the product of an unknown underlying common cause. Some research suggests that these brain anomalies may be the result of childhood stress, or prolonged or severe stress.
Historically, fibromyalgia has been considered either a musculoskeletal disease or neuropsychiatric condition. Although there is as yet no cure for fibromyalgia, some treatments have been demonstrated by controlled clinical trials to be effective in reducing symptoms, including medications, behavioral interventions, patient education, and exercise. The most recent approach of a diagnosis of fibromyalgia involves pain index and a measure of key symptoms and severity.
Fibromyalgia has been recognized as a diagnosable disorder by the National Institutes of Health and the American College of Rheumatology. Fibromyalgia, a central nervous system disorder, is described as a 'central sensitisation syndrome' caused by neurobiological abnormalities which act to produce physiological pain and cognitive impairments as well as neuro-psychological symptomatology. Despite this there are some members of the medical community who do not consider fibromyalgia a disease because of a lack of abnormalities on physical examination and the absence of objective diagnostic tests.