Fibromyalgia is challenging to diagnose. Some people see a number of doctors—and seek answers for years—before getting an accurate diagnosis.
Who Can Diagnose Fibromyalgia
A family practice physician, internist, or rheumatologist can diagnose fibromyalgia. In some cases, the patient is referred to a rheumatologist for a diagnosis after being examined by a family practice physician or internist. Rheumatologists are internists or pediatricians with additional training in arthritis and other rheumatic diseases, including fibromyalgia.
There is no widely accepted medical test to diagnose fibromyalgia. Instead, diagnostic tests are performed to see if another condition could be causing the symptoms.
Blood tests are usually ordered to rule out conditions with similar symptoms. Other tests will depend on the symptoms described, but may include X-rays or an electromyography (EMG), to evaluate muscles’ electrical activity.
Patients typically undergo a thorough physical, with the patient alerting the doctor to areas causing pain. Some doctors may press lightly on the areas of the body called tender points, discreet areas of tenderness in the muscular and tendinous tissue of those with fibromyalgia.
These areas are at uniform and consistent sites in fibromyalgia patients, who are generally unaware of the tender points until a doctor presses on them.
The doctor may also ask whether any relatives have or have had similar symptoms, since fibromyalgia seems to have a genetic component.
Criteria for Diagnosis
Guidelines for a fibromyalgia diagnosis have evolved in recent decades. Criteria developed in 1990 emphasized pain symptoms and a physical exam that involved checking on 18 tender points.
In 2010, the American College of Rheumatology revised its criteria for a fibromyalgia diagnosis to take into account symptoms other than pain and increased the number of tender points to 19.1
The 2010 guidelines still considered tender points an important part of the diagnosis, but no longer required that pain be felt in 11 of these points, as determined by a physical exam that involved the doctor pushing down on these locations.2 Some variations on diagnostic criteria have been proposed, but doctors generally follow the 2010 guidelines.
Before being considered for a diagnosis of fibromyalgia, symptoms must have been experienced for at least three months and all other causes for the symptoms ruled out.
If that is the case, the diagnosis is then based on scores in two major areas, widespread pain and symptom severity, experienced by the patient during the past week. To be classified as widespread, the pain must be on the upper part of the body as well as below the waist. It must also be felt on both sides.
Widespread Pain Index
Patients are typically asked if they have pain in any of 19 potential tender points. Each tender point where pain is experienced counts as 1 point, with the score on this index ranging from 0 to 19.
Symptom Severity Score
Fatigue, waking unrefreshed, and cognitive symptoms are ranked by severity in this assessment. The extent of additional symptoms typically associated with fibromyalgia is recorded, but these are not ranked by severity. Possible scores are between 0 and 12.
A major step in the diagnosis is met when the scores match one of these categories:
- A Widespread Pain Index score of 7 or more, and a Symptom Severity Scale of 5 or more.
- A Widespread Pain Index score of 3 to 6 and a Symptom Severity Scale of 9 or more.
Some patients may be provided with an illustrated chart showing tender points and a checklist to note symptoms.
Preparing for Questions
A detailed discussion of symptoms is especially important due to the likelihood of coexisting conditions. Thinking through the answers to these questions before the visit can help the doctor hone in on a diagnosis:
- What symptoms have been experienced?
- How would you describe the pain?
- How long have these symptoms existed?
- What makes the symptoms worse?
- What makes the symptoms less noticeable?
- What effect does exercise have?
Writing symptoms and questions down in advance of the visit can be a good way to ensure that nothing is forgotten.
Conditions Similar to Fibromyalgia
The non-specific nature of many fibromyalgia symptoms, such as fatigue, can lead to an incorrect diagnosis. The diagnosis may be confused with other conditions, including, but not limited to:
- Chronic fatigue syndrome (myalgic encephalomyelitis)
- Depression and anxiety
- Myofascial pain syndrome, a regional pain syndrome
- Multiple sclerosis, myasthenia gravis, and other neurological conditions
- Other rheumatic conditions, such as rheumatoid arthritis, osteoarthritis, Sjogren’s Syndrome, and systemic erythematosus lupus
- Underactive thyroid, or hypothyroidism
While symptoms for these conditions may overlap, treatments generally do not. Getting a correct diagnosis is the first step in learning what treatments and lifestyle changes may make life easier with fibromyalgia.
Fortunately, many fibromyalgia patients see improvement in their symptoms after the diagnosis of fibromyalgia has been established and their "demon has been named," which can be a relief in and of itself.