How Is Fibromyalgia Diagnosed?

Fibromyalgia syndrome, or FMS, can be difficult to diagnose, since there is no laboratory test or X-ray that can conclusively identify it. Such tests can be useful, however, in ruling out diseases with similar symptoms, such as hypothyroidism. People with fibromyalgia are sometimes diagnosed with the condition years after they first seek medical attention. Talk to your doctor about your medical history — your doctor will find it useful.

To help doctors determine whether their patients have fibromyalgia, the American College of Rheumatology has developed criteria for diagnosing the condition. Researchers have determined that in spite of the syndrome’s varied and wide-ranging symptoms, most patients complain of a unique symptom: pain when a series of “tender points” along their bodies are probed. These 18 tender points are actually nine symmetrical pairs of points from the skull to the knees. The points are located near areas where muscle is attached to bone and include spots at the base of the skull and the tops of the hips, on the shoulder blades and the breastbone, and on the outer edges of the forearms, about an inch below the elbow. According to the American College of Rheumatology, you have fibromyalgia if you have had pain in at least 11 of these 18 tender points — covering all four quadrants of your body — for at least three months.

Doctors may use an instrument called a dolorimeter, which evenly distributes pressure, to measure pain at the tender points. Or the doctor may use his or her finger, pressing down until the fingernail bed turns white, which approximates about 4 kilograms of pressure. Usually, however, they don’t need to press that hard before fibromyalgia sufferers feel pain. Although people with fibromyalgia are aware of pain, they may not realize that these specific points are sore until a doctor examines them.

People who have pain in fewer than 11 of the tender points may still have a condition similar to classic fibromyalgia. Some doctors may also diagnose a patient with fibromyalgia if he or she has had pain in 3 out of 4 quadrants of his or her body for at least three months.

Since the medical community officially recognized fibromyalgia only recently and since some doctors are still skeptical of its existence, it is important to see a doctor familiar with fibromyalgia and its treatment. Most rheumatologists — doctors who specialize in arthritis and rheumatism — know how to diagnose the syndrome. However, medical schools didn?t teach the test before 1985. Many still don?t.