Fibromyalgia (FMS)
How is it diagnosed?
The difficulty diagnosing fibromyalgia is that there is no clear-cut test to determine fibromyalgia. No evidence of it appears on X-rays or in laboratory test results. There is no diagnostic marker in the blood. People with fibromyalgia often look healthy and have no outward signs of pain or fatigue.
Instead, fibromyalgia is diagnosed by the identification of symptoms and the exclusion of other conditions. In 1990, the American College of Rheumatology, the official body of doctors who treat arthritis and related conditions, developed criteria for the diagnosis of fibromyalgia. It is diagnosed when the patient displays the following symptoms:
- A history of widespread pain (pain on both sides of the body and above and below the waist) that is present for at least three months.
- Pain in at least 11 of 18 tender-point sites. These points are considered positive when pain is felt upon the application of 4 kilograms of pressure – the approximate amount of pressure required to blanch the examiners’ fingernail.
It is important to note, however, that these criteria were written to help researchers identify patients for clinical trials, not for diagnosing the disease in individual people. At least half of the individuals who have the clinical diagnosis of fibromyalgia will not fulfill this definition. Your doctor will listen to you explain all of your symptoms, will order laboratory tests to rule out other conditions with similar symptoms, and will use his or her experience to decide if you have fibromyalgia.
Related Conditions
The following simulate fibromyalgia or occur concurrently with the condition:
- Hypothyroidism [link]
- Polymyalgia rheumatica [link]
- Hepatititis C infection
- Sleep apnea
- Parvovirus infection
- Cervical stenosis/Chiari malformation
- Chronic fatigue syndrome
- Medications such as lipid-lowering drugs or antiviral agents
And less commonly:
- Autoimmune disorders, such as rheumatoid arthritis and lupus, especially early in the course of the disease
- Endocrine disorders, such as Addison’s disease, Cushing’s syndrome and hyperparathyroidism
- Lyme disease [link]
- Eosinophilia-myalgia syndrome
- Malignancy
- Tapering of corticosteroids
The diagnostic process can take years, partly due to the fact that fibromyalgia remains unfamiliar to many people, including doctors. Fortunately, a greater understanding of fibromyalgia now exists within the medical community. Finding the right doctor can help expedite diagnosis. A rheumatologist or a doctor at a pain clinic could help make the diagnosis.
