I have tingling, numbness, weakness and pain in my fingers and hands. what's going on?

Nerve compression: May be carpal tunnel syndrome. Sleeping in a splint may help, but if symptoms persist or worsen see a hand surgeon.

Many Possibilities: With out an examination - one can only list a long list of possible diagnoses - basically if the tingling and numbness is that intrusive you need to be evaluated by your pcp or by a neurologist.