Testing for Fibromyalgia · Thyroid hormone tests. · Antinuclear antibody (ANA) test. · C-reactive protein (CRP). · Erythrocyte sedimentation rate (ESR or sed rate). Tests to check for some of these conditions include urine and blood tests, although you may also have X-rays and other scans. If you're found to have another. There is no widely accepted medical test to diagnose fibromyalgia. Instead, diagnostic tests are performed to see if another condition could be causing the.