my hands are shaking funny

Hello all!  I was curious with this semi qick question.  I have been diagnosed with fibro, but the rheumy says I don't have enough symptoms to diagnose me with RA or anything else.  So with the pain in my feet and hands being chalked up to the fibro getting worse, why then do my hands shake like I've got arthritis or parkinsins?  I was simply putting a piece of paper aside during work and ya know how when it droops you flick your hand at the wrist to give it that fluff to make it so it actually gets on the desk and not on the floor.  That's when the shaking happened.  The shaking has been for a while.  I think its because when I was a kid I was pretty active and did fall at least 2 major times where (as the doc said) I bruised my wrists.  I can put my hands out horizontial and flex my hand up and then down and they shake a little going up but more so going down.  Now they are shaking when I am simply moving a piece of paper less than 2 feet away from me.  What could it mean?  I don't have great health insurance and this comes off as something that I would have to have a lot of follow ups for and to boot its not totally affecting my work or driving or home life.  I guess things like reading a book one-handed and holding a glass at a party type scenario its affecting those functions.  Could you guys and gals help me to theorize what it could be?  I would greatly appreciate it.