Picking hand locking up during Live Gigs: Help!

As the title of this post suggests I have been having an ongoing problem with my picking hand when I play live shows. For nearly every show at some point during the set my hand will begin to tense up and cause pain to the point where I have to drop the pick and play fingerstyle. I don't think I'm holding the pick wrong although I may be using a "death grip" I play lead and rhythm guitar in my band and I usually use the orange dunlop picks. I like the sound of playing with a pick but I am considering going only fingerstyle as I don't have this problem when I do that. Please help! This is a real problem for me and I want to continue to play live! Also, if I opt to go pure fingerstyle should I get a compression pedal to balance out the volume of my playing? Thanks again TDPRI!

If it helps this is the music I play: http://www.newtooth.bandcamp.com

I used to have that happen but on my fretting hand. My index finger and thumb would "lock up" research led me to a condition called "trigger finger" I was able to cure the problem over time by with stretches and exercises and more importantly, by focusing on removing the stress in my hand and learning to pay more relaxed. Best of luck to you I hope it find our answer.

Try and ascertain where the tension starts Gerald - i.e can often have its roots further up in the shoulder / neck region and creeps down the arm over time - your hands might feel relaxed before the gig but your shoulders and neck could be in spasm (lugging heavy gear, and bad guitar strap placement dont help!)