Hi and yes to all that has been said. But lets see if we can find the source of this problem.
Check your bass, does it have balance issues like neck dive, that is when you let the bass go the neck falls to the ground? This will but extra strain in the hands as you have to support and play.
Did it start as a result of increased playing or doing something different in the work place?
Have you been un-well recently?
Are you using an over developed technique? By that i mean wrist angle to allow the thumb to stay low behind the neck to allow full access to the fretboard all the time. If you play a rock/blues style this technique is not nessesary and simpler safer one will do.
Just a few things to consider in your playing. if you want to disscuss it more drop me a PM or check out the blogs at
www.myspace.com/vintageprecisionbass
for more info. I would see a medical profesional now for a medical view, but if not now and it continues or gets worse see a medical profesional.
