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.
Evidence from research conducted in the last three decades has revealed abnormalities within
the central nervous system affecting brain regions that may be linked both to clinical symptoms and
research phenomena. These studies show a correlation, but not causation. Some research suggests
that alterations in the central nervous system might be the result of childhood stress, or prolonged
or severe stress.
The defining symptoms of fibromyalgia are chronic, widespread pain, fatigue, and heightened pain in
response to tactile pressure (allodynia). Other symptoms may include tingling of the skin, prolonged
muscle spasms, weakness in the limbs, nerve pain, muscle twitching, palpitations, functional bowel
disturbances, and chronic sleep disturbances.
Many patients experience cognitive dysfunction (known as "brain fog" or "fibrofog"),
which may be characterized by impaired concentration, problems with short and long-term memory,
short-term memory consolidation, impaired speed of performance, inability to multi-task,
cognitive overload, and diminished attention span. Fibromyalgia is often associated with anxiety,
and depressive symptoms.
Other symptoms often attributed to fibromyalgia that may possibly be due to a comorbid disorder include
myofascial pain syndrome, also referred to as chronic myofascial pain, diffuse non-dermatomal
paresthesias, functional bowel disturbances and irritable bowel syndrome (possibly linked to lower
levels of ghrelin), genitourinary symptoms and interstitial cystitis, dermatological disorders,
headaches, myoclonic twitches, and symptomatic hypoglycemia. Although fibromyalgia is classified based on
the presence of chronic widespread pain, pain may also be localized in areas such as the shoulders, neck,
low back, hips, or other areas. Many sufferers also experience varying degrees of myofascial pain and have
high rates of comorbid temporomandibular joint disorder. 20–30% of patients with rheumatoid arthritis and
systemic lupus erythematosus may also have fibromyalgia.