Information for Fibromyalgia Australia is reproduced with the permission of the Canadian National ME/FMS Action Network (2005). Fibromyalgia Syndrome is multifactorial and clinical presentations vary. Currently research is underway to develop more detailed clinical markers and to categorise different subsets of FMS.

The Research Case Definition of FMS (Download Canadian PDF 102kB) requires:

  • Widespread pain that lasts at least 3 months. Widespread means that there is pain above and below the waist, and on both sides of the body.
  • 11 or more of the 18 defined tender points.

Additional Clinical Symptoms and Signs

It is important to record those additional Clinical Symptoms & Signs (Download PDF of symptoms 111kB) can contribute to the patient’s burden of illness. Two or more of these features are usually present in most FMS patients by the time they seek medical attention. On the other hand, it is uncommon for any individual FMS patient to have all of the associated symptoms or signs. As a result, the clinical presentation of FMS may vary somewhat between patients, and the patterns of involvement may eventually lead to the recognition of FMS clinical subgroups. These additional clinical symptoms and signs are not required for the research classification of FMS but they are still clinically important.

To support clinicians in managing fibromyalgia, the following clinical symptoms and signs are itemized and described in an attempt to expand the compulsory pain criteria into a working Clinical Case Definition of FMS.

  • Neurological Manifestations: neurological difficulties are often present such as hypertonic and hypotonic muscles; musculoskeletal asymmetry and dysfunction involving muscles, ligaments and joints; atypical patterns of numbness and tingling; abnormal muscle twitch response, muscle cramps, muscle weakness and fasciculations. Headaches, TMJ disorder, generalized weakness, perceptual disturbances, spatial instability, and sensory overload phenomena often occur.
  • Neuro-cognitive Manifestations:some neuro cognitive difficulties usually are present. These include impaired concentration and short-term memory consolidation, impaired speed of performance, inability to multi-task, and/or cognitive overload.
  • Fatigue:There is persistent and reactive fatigue accompanied by reduced physical and mental stamina, which often interferes with the patient’s ability to exercise.
  • Sleep Dysfunction:the patient experiences unrefreshing sleep. This is usually accompanied by sleep disturbances including insomnia, frequent nocturnal awakening, nocturnal myoclonus, and/or restless leg syndrome.
  • Autonomic and/or Neuroendocrine Manifestations:These manifestations include cardiac arrhythmias, neurally mediated hypotension, vertigo, vasomotor instability, sicca syndrome, temperature instability, heat/cold intolerance, respiratory disturbances, intestinal and bladder motility disturbances with or without irritable bowel or bladder dysfunction, dysmenorrhea, loss of adaptability and tolerance for stress, emotional flattening, lability, and/or reactive depression.
  • Stiffness:It is common for generalized or regional stiffness that is most severe upon awakening and typically lasts for hours, to occur. Stiffness can return during periods of inactivity during the day.