A couple of days ago I started having slight pain in my left thumb while at work. As the day went on the pain increased and spread throughout most of my left hand. The pain is not usually constant but very severe when I put any stress on it at all (twist something, make a fist, try to lift with that hand, etc). I really don't believe it to be carpal tunnel from what i've read and heard, but I didn't injure the hand in any way recently either. Could it be a pinched nerve or something along those lines? Please help...The pain is intense and I don't have a clue!!!

P.S. There is no visible swelling, but the painful area feels very tight