Could there be a reason I shake...?

They may be some tremors, which is not anything serious, maybe some vitamin deficiency. It must have something to do with your nerves or muscles, but Cowabanga dude is right, you should go see a doctor so he can diagnose it. If it's something acute, then it's good to get it treated, the sooner the better. Just don't ignore it so you don't have to keep worrying about it.