Fibromyalgia is a term used to describe widespread pain which is a function of amplification of central (brain) pain processing. However, most thoughtful Rheumatologists will follow three important principles when they meet someone who has been previously diagnosed with 'fibromyalgia'. So sequentially:

  1. Does the person really have fibromyalgia? That is to say, is there a previously-undiagnosed identifiable condition causing the pains mimicking fibromyalgia? 

  2. Is there an underlying condition causing pain but is there fibromyalgia also (i.e. central brain mediated amplification of pains from the underlying condition)? 

  3. If there are fibromyalgia pains then what are the main influences (‘drivers’) of it (i.e. of pain amplification). Two of the commonest ‘drivers’ of fibromyalgia pain are poor sleep (non-restorative) and the intrusion of unresolved traumatic psychological issues.

Some conditions that can be mistaken for fibromyalgia by the unwary include: psoriasis-related musculoskeletal disease (enthesitis and bone lesions cause the pain), inflammatory bowel disease related musculoskeletal disease), sarcoidosis, SLE ('lupus') and other autoimmune connective tissue diseases, osteomalacia and primary hyperparathyroidism.
For anyone with widespread persistent pains, often a delay in the diagnosis of any of the above causes (which are all chronic diseases) and being in a position of having been given multiple different diagnoses, leads understandably to confusion, anxiety and frustration - all potential triggers for pain amplification, poor sleep and fatigue (i.e. fibromyalgia!). 

Some patient information about fibromyalgia: