Something is wrong with my left arm. What is it?

My left arm is in serious pain. It hurts so bad!!! I woke up this morning feeling fine and then all of a sudden WHAM my fingers, wrist and shoulder were all achy. It keeps getting worse and worse. Right now my shoulder doesn't hurt anymore but my wrist and fingers are killing me!!! It hurts to move but it hurts whether I move it or not! It's hurting from the inside, like it feels that my bones are just hurting for no reason. There's no swelling or discoloration. BUT IT HURTS!!!