There is no obvious, objective method (such as laboratory or imaging tests) for diagnosing fibromyalgia. The criteria used to study fibromyalgia are very helpful, particularly if the patient does not have another disorder, such as depression or arthritis, which could complicate the diagnosis. Failure to meet the criteria, however, does not rule out fibromyalgia. Fibromyalgia should be suspected in any person who has muscle and joint pain with no identifiable cause.
Because many patients do not meet the current fibromyalgia criteria, the American College of Rheumatology (ACR) has proposed a new set of diagnostic criteria that take into consideration symptoms such as fatigue, sleep disturbance, and cognitive problems, in addition to pain.
Criteria for Classifying Fibromyalgia
In 1990, the ACR set the following criteria for classifying fibromyalgia:
A. Widespread pain must be present for at least 3 months. This pain must appear in all of the following locations:
- Both sides of the body
- Above and below the waist
- Along the length of the spine
B. Pain in at least 11 of 18 specific areas called tender points on the body. The pain experienced when pressing on a tender point is very localized and intensely painful (not just tender). Tender points are located in the following areas:
- The left or right side of the back of the neck, directly below the hairline
- The left or right side of the front of the neck, above the collarbone (clavicle)
- The left or right side of the chest, right below the collarbone
- The left or right side of the upper back, near where the neck and shoulder join
- The left or right side of the spine in the upper back between the shoulder blades (scapula)
- The inside of either arm where it bends at the elbow
- The left or right side of the lower back, right below the waist
- Either side of the buttocks below the hip bones
- Either kneecap
New criteria. The ACR's proposed new criteria would replace the tender point examination with a widespread pain index (WPI), which counts the number of areas where the patient has felt pain in the last week. It would also include a symptom severity scale (SSS), which rates on a scale of 0 to 3 the severity of three common fibromyalgia symptoms:
- Unrefreshing sleep
- Cognitive symptoms
Another three points can be added for these additional symptoms:
- Irritable bowel syndrome
The WPI and SS scores are totaled to create a final score of between 0 and 12. To meet the criteria for a fibromyalgia diagnosis, a patient would have seven or more pain areas and a symptom severity score of five or more; or three to six pain areas and a symptom severity score of nine or more. The symptoms must have been present for at least 3 months.
Review Date: 12/27/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.