What Causes Severe Pain In The Wrist?

I have had wrist issues in the past, and recently its been bothering me. Today I hit my wrist against the wall, accidentally, and theres now pain shooting up my whole arm anytime I move my hand or wrist. It's not swollen or bruised..and I've iced it...but I hit it almost three hours ago and it still hurts! Whats wrong ?:(