FM is a medical condition characterized and defined by the hallmark of chronic widespread nonarticular musculoskeletal pain.
Another characteristic feature is that no physical reasons for the pain, such as injury or inflammation, can be localized -- in fact, this often leads to belief by health care workers that patients are simply "malingering," and this can potentially delay diagnosis and treatment. In fact, many patients with FM are not diagnosed, and few patients are receiving appropriate treatment. Current thinking based on the latest evidence is that FM is not a discrete illness but is rather part of a large continuum of central pain and somatic syndromes caused by dysfunction of central pain processing. It may even be a more global problem with sensory processing that is not just limited to processing of pain because people with FM are also sensitive to several different types of stimuli.
Diffuse or multifocal pain
Aching all over
Stiffness that is typically present upon arising in the morning and improves as the day progresses
Neurologic qualities (eg, aching, numbness, tingling, burning)
Dysthesias or paresthesias
Pain "moves around" to various parts of the body
Pain comes and goes very rapidly, or "waxes and wanes"
Discomfort occurs with touch or when wearing tight clothing
Low back pain that radiates into the buttocks and legs
Pain and tightness in the neck and across the upper posterior shoulders
Pain in visceral structures
Two other important features of FM pain are a subjective swollen joint feeling without objective swelling and paresthesias without objective neurologic findings.[1,3] In addition, the duration of the pain is an important feature to determine because patients with long-standing pain are more likely to have FM.