What Causes A Sharp Pain In Hand While Moving?

My right hand often has sharp pain when I move it. it is unpredictable and often has no pain at all. The pain is so intense it stops me.

On my left hand the ring finger - mainly at the knuckle joint in my hand - is tender and at times the finger will not open or close with the other fingers. It gets to a point and then snaps down. This is worse when I have been asleap. It is tender to touch.