I think the answer is source of influence
It is a diagnosis that is symptom based. There are no lab tests or other tests that can test for it.
Symptoms are usually Chronic muscle pain, moderate to severe fatigue, un-refreshing sleep, sensitivity to smells, light, noise. Headaches. There 18 trigger points that Dr's test to see if patient experiences pain.
Generally you feel like you have the flu but never get better.
Causes temporary weight gain due to intake of more fluids. When you eat salts, they absorb more water in the body, making one look/feel more "full", which can cause a temporary gain in weight when stepping on a scale. For clarification, the weight temporarily gained if referred to as "water weight"
