I have heard that fibromyalgia is an umbrella term used to cover symptoms that are unexplained. often it is just another set of symptoms. really?

You heard wrong: Fibromyalgia is a neurologic disorder with specific diagnostic criteria. It is not a waste basket diagnosis.

Fibromyalgia: Fibromyalgia is an endurance disorder of muscle. When you exceed the endurance capabilities of the muscle, the muscle locks down into painful spasms to prevent tearing of the muscle. Over time the pain becomes centralized in the brain. Generally something causes the endurance to be low in the first place and thus triggers fibromyalgia.

Fibromyalgia: That is incorrect. It is a central pain, neurologic disorder with very specific diagnostic criteria well defined and refined by the american college of rheumatology.