Question: How Is Fibromyalgia Diagnosed?
Fibromyalgia is often difficult to diagnose since its symptoms overlap with many other rheumatic conditions. Are there diagnostic laboratory tests for fibromyalgia? What are the diagnostic criteria for fibromyalgia? What are fibromyalgia tender points? How is fibromyalgia diagnosed?
Fibromyalgia Diagnosis Is Difficult
Research shows that people with fibromyalgia typically see many doctors before receiving the diagnosis. One reason for this may be that pain and fatigue, the main symptoms of fibromyalgia, overlap with many other conditions. Doctors rule out other potential causes of the symptoms before making a diagnosis of fibromyalgia.
No Diagnostic Laboratory Tests for Fibromyalgia
Another reason fibromyalgia diagnosis remains difficult is that there are currently no diagnostic laboratory tests for fibromyalgia; standard laboratory tests fail to reveal a physiologic reason for pain. Because there is no generally accepted, objective test for fibromyalgia, some doctors unfortunately may conclude a patient's pain is not real, or they may tell the patient there is little they can do.
Diagnostic Criteria for Fibromyalgia
A doctor familiar with fibromyalgia, however, can make a diagnosis based on two criteria established by the American College of Rheumatology:
- a history of widespread pain lasting more than 3 months
- the presence of tender points
Pain is considered to be widespread when it affects all four quadrants of the body; that is, you must have pain in both your right and left sides as well as above and below the waist to be diagnosed with fibromyalgia.
Fibromyalgia Tender Points
The American College of Rheumatology also has designated 18 sites on the body as possible tender points. For a fibromyalgia diagnosis, a person must have 11 or more tender points.
One of these predesignated sites is considered a true tender point only if the person feels pain upon the application of 4 kilograms of pressure to the site. People who have fibromyalgia certainly may feel pain at other sites, too, but those 18 standard possible sites on the body are the criteria used for classification.
NIH Publication No. 04-5326, June 2004