Carpal Tunnel syndrome is definitely something to be concerned about when airbrushing. A couple of techniques I learned to guard against this are to first of all try and relax your hand, meaning you don't need the death grip on the airbrush to achieve good results. When my hand starts to cramp up, the death grip is usually the culprit. The other technique is to change the way you trigger the airbrush. Do not use the very tip of your index finger, which is what I always did and still do at times. This causes stress on you entire hand and especially your wrist. Instead, place the back of the trigger into that first crease of the index finger. Tuck the trigger snugly right into that first crease nearest the tip of the finger. Now all you have to do is move your index finger up and down to trigger the airbrush instead of pulling and pushing the trigger back and forth. It does take some practice to relearn to trigger the airbrush this way, but your wrist will thank you for it in the long run.