The diagnosis is made by history and physical examination.
Note: Fibromyalgia is a diagnosis of exclusion!To rule out fibromyalgia, testing of the following laboratory parameters is recommended:
- Small blood count
- Differential blood count
- Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate) – eg due topossible polymyalgia rheumatica, rheumatoid arthritis.
- Creatinine kinase (CK) – due toe.g. muscle diseases.
- Calcium – exclusion of hypercalcemia (calcium excess).
- TSH (thyroid-stimulating hormone), basal (eg, due toHypothyroidism – hypothyroidism).
- 25-Dihydroxy vitamin D – exclusion of vitamin D deficiency (due toassociation between FMS and 1,25-dihydroxy vitamin D deficiency (odds ratio 1.41 [95% confidence interval 1.00-2.00] after adjusting for confounding variables)]
- Borrelia antibody (IgG, CSF/serum).
- Yersinia antibodies (IgA, IgG, IgM)
- CCP-Ak (cyclic citrullinated peptide) – in suspected rheumatic diseases.
- Auto-Ak (IgG) against cell nuclear antigens (synonyms: ANA, ANF, antinuclear factors).
- Auto-Ak against smooth muscle (synonyms: SMA, ASMA, actin).
- Myoglobin
- Rheumatoid factor (RF)
Depending on the history and physical examination findings, additional laboratory tests may be useful.