From the Guidelines
Fibromyalgia diagnosis is primarily based on clinical criteria, and bloodwork is used to rule out other conditions that may cause similar symptoms, with no single test definitively diagnosing the condition. The diagnosis of fibromyalgia remains a challenge, with a prevalence of 2% in the general population, and it often takes more than 2 years for a diagnosis to be made, as stated in the 2017 EULAR revised recommendations for the management of fibromyalgia 1. When it comes to bloodwork, common tests include:
- Complete blood count (CBC)
- Comprehensive metabolic panel
- Thyroid function tests (TSH, T3, T4)
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP)
- Rheumatoid factor
- Antinuclear antibody tests These tests help exclude conditions like rheumatoid arthritis, lupus, thyroid disorders, and other inflammatory or autoimmune diseases. Additionally, vitamin D levels and iron studies may also be checked as deficiencies can cause similar symptoms. It's essential to note that fibromyalgia is ultimately diagnosed based on clinical criteria, including widespread pain lasting at least three months, fatigue, sleep disturbances, and cognitive difficulties, rather than laboratory findings, as there is no specific blood test that can definitively diagnose fibromyalgia, according to the EULAR revised recommendations 1.
From the Research
Bloodwork for Diagnosing Fibromyalgia
The diagnosis of fibromyalgia is primarily based on exclusion, and bloodwork plays a crucial role in ruling out other causes of joint or muscle pain. The following blood tests are recommended:
- Complete blood count (CBC) 2
- Erythrocyte sedimentation rate (ESR) 2, 3
- Liver function tests 2
- Hepatitis C antibody 2
- Calcium 2
- Thyrotropin 2
- C-reactive protein (CRP) 3
- Neutrophil lymphocyte ratio (NLR) 3
- Mean platelet volume (MPV) 3, 4
- Platelet distribution width (PDW) 3
Inflammatory Markers
Research suggests that inflammatory markers, such as ESR, CRP, NLR, and MPV, may be useful in diagnosing fibromyalgia and assessing disease severity 3. These markers are often elevated in patients with fibromyalgia, indicating a possible inflammatory basis for the disease.
Cardiovascular Risk Factors
Studies have also shown that patients with fibromyalgia may have an increased risk of cardiovascular disease, and mean platelet volume (MPV) may be a useful marker for assessing this risk 4. Elevated MPV levels have been found in patients with fibromyalgia, suggesting increased platelet activation and a higher risk of future cardiovascular disease.