rcts found that transcranial direct current stimulation (tdcs) of over 4 weeks can decrease pain in patients with fibromyalgia. a 2021 meta-analysis of multiple intervention types concluded that magnetic field therapy and transcranial magnetic stimulation may diminish pain in the short-term, but conveyed an uncertainty about the relevance of the result. several 2022 meta-analyses focusing on transcranial magnetic stimulation found positive effects on fibromyalgia. repetitive transcranial magnetic stimulation improved pain in the short-term and quality of life after 5–12 weeks. repetitive transcranial magnetic stimulation did not improve anxiety, depression, and fatigue. transcranial magnetic stimulation to the left dorsolateral prefrontal cortex was also ineffective. hyperbaric oxygen therapy hyperbaric oxygen therapy (hbot) has shown beneficial effects in treating chronic pain. however, treating fibromyalgia with hyperbaric oxygen therapy is still controversial, in light of the scarcity of large-scale clinical trials. in addition, hyperbaric oxygen therapy raises safety concerns due to the oxidative damage that may follow it. an evaluation of nine trials with 288 patients in total found that hbot was more effective at relieving fibromyalgia patients' pain than the control intervention. in most of the trials hbot improved sleep disturbance, multidimensional function, patient satisfaction, and tender spots. unfortunately, 24% of the patients experienced negative outcomes. prognosis although in itself fibromyalgia is neither degenerative nor fatal, the chronic pain of fibromyalgia is pervasive and persistent. most people with fibromyalgia report that their symptoms do not improve over time. however, most patients learn to adapt to the symptoms over time. the german guidelines for patients explain that: the symptoms of fibromyalgia are persistent in nearly all patients. total relief of symptoms is seldom achieved. the symptoms do not lead to disablement and do not shorten life expectancy. an 11-year follow-up study on 1,555 patients found that most remained with high levels of self-reported symptoms and distress. however, there was a great deal of patient heterogeneity accounting for almost half of the variance. at the final observation, 10% of the patients showed substantial improvement with minimal symptoms. an additional 15% had moderate improvement. this state, though, may be transient, given the fluctuations in symptom severity. a study of 97 adolescents diagnosed with fibromyalgia followed them for eight years. after eight years, the majority of youth still experienced pain and disability in physical, social, and psychological areas. at the last follow-up, all participants reported experiencing one or more fibromyalgia symptoms such pain, fatigue, and/or sleep problems, with 58% matching the complete acr 2010 criteria for fibromyalgia. based on the wpi and ss score cut-points, the remaining 42% exhibited subclinical symptoms. pain and emotional symptom trajectories, on the other hand, displayed a variety of longitudinal patterns. the study concluded that while most patient's fibromyalgia symptoms endure, the severity of their pain tends to reduce over time. baseline depressive symptoms in adolescents appear to predict worse pain at follow-up periods. epidemiology fibromyalgia is estimated to affect 2–4% of the population. females are affected about twice as often as males based on criteria as of 2014. history chronic widespread pain had already been described in the literature in the 19th century but the term fibromyalgia was not used until 1976 when dr p.k. hench used it to describe these symptoms. many names, including "muscular rheumatism", "fibrositis", "psychogenic rheumatism", and "neurasthenia" were applied historically to symptoms resembling those of fibromyalgia. the term fibromyalgia was coined by researcher mohammed yunus as a synonym for fibrositis and was first used in a scientific publication in 1981. fibromyalgia is from the latin fibra (fiber) and the greek words myo (muscle) and algos (pain). historical perspectives on the development of the fibromyalgia concept note the "central importance" of a 1977 paper by smythe and moldofsky on fibrositis. the first clinical, controlled study of the characteristics of fibromyalgia syndrome was published in 1981, providing support for symptom associations. in 1984, an interconnection between fibromyalgia syndrome and other similar conditions was proposed, and in 1986, trials of the first proposed medications for fibromyalgia were published. a 1987 article in the journal of the american medical association used the term "fibromyalgia syndrome" while saying it was a "controversial condition". the american college of rheumatology (acr) published its first classification criteria for fibromyalgia in 1990. later revisions were made in 2010, 2016, and 2019. society and culture economics people with fibromyalgia generally have higher healthcare costs and utilization rates. a review of 36 studies found that fibromyalgia causes a significant economic burden on health care systems. annual costs per patient were estimated to be up to $35,920 in the us and $8,504 in europe. controversies fibromyalgia was defined relatively recently. in the past, it was a disputed diagnosis. frederick wolfe, lead author of the 1990 paper that first defined the diagnostic guidelines for fibromyalgia, stated in 2008 that he believed it "clearly" not to be a disease but instead a physical response to depression and stress. in 2013, wolfe added that its causes "are controversial in a sense" and "there are many factors that produce these symptoms – some are psychological and some are physical and it does exist on a continuum". some members of the medical community did not consider fibromyalgia a disease because of a lack of abnormalities on physical examination and the absence of objective diagnostic tests. in the past, some psychiatrists have viewed fibromyalgia as a type of affective disorder, or a somatic symptom disorder. these controversies do not engage healthcare specialists alone; some patients object to fibromyalgia being described in purely somatic terms. as of 2022, neurologists and pain specialists tend to view fibromyalgia as a pathology due to dysfunction of muscles and connective tissue as well as functional abnormalities in the central nervous system. rheumatologists define the syndrome in the context of "central sensitization" – heightened brain response to normal stimuli in the absence of disorders of the muscles, joints, or connective tissues. because of this symptomatic overlap, some researchers have proposed that fibromyalgia and other analogous syndromes be classified together as central sensitivity syndromes. notes shoulder girdle (left & right), upper arm (left & right), lower arm (left & right), hip/buttock/trochanter (left & right), upper leg (left & right), lower leg (left & right), jaw (left & right), chest, abdomen, back (upper & lower), and neck.: 607 somatic symptoms include, but are not limited to: muscle pain, irritable bowel syndrome, fatigue or tiredness, problems thinking or remembering, muscle weakness, headache, pain or cramps in the abdomen, numbness or tingling, dizziness, insomnia, depression, constipation, pain in the upper abdomen, nausea, nervousness, chest pain, blurred vision, fever, diarrhea, dry mouth, itching, wheezing, raynaud's phenomenon, hives or welts, ringing in the ears, vomiting, heartburn, oral ulcers, loss of or changes in taste, seizures, dry eyes, shortness of breath, loss of appetite, rash, sun sensitivity, hearing difficulties, easy bruising, hair loss, frequent or painful urination, and bladder spasms.: 607