Carpal Tunnel Syndrome can be a real pain!!
I have/had it in both hands. I had the surgery on my right hand nearly 2 years ago. If I had it to do all over again, I would have the surgery in a heartbeat!! I have NO problems in that hand now. My left hand...well, that's another story. I have been contemplating surgery for the left hand, but it isn't nearly as bad as the right was, so I'm delaying it for awhile. I don't use that hand as much.
Here's an interesting link:
http://www.ninds.nih.gov/disorders/carpal_tunnel/detail_carpal_tunnel.htm
Wearing a splint at night is one of THE best ways to get some relief. It takes some getting used to, but it does help. It doesn't happen overnight though. I would suggest wearing a splint 24 hours a day (or as much as possible) for about 2 weeks (give the swelling in the area a chance to go down) then wear the brace at night for at least 6 weeks (maybe indefinitely).
There are other things you can do...
Drink lots of water. Pregnant women sometimes get "temporary" CTS because of water retention/swelling. This will help some, but not necessarily take care of all the problem.
I have heard vitamin B6 works wonders...and I've also heard licorice root has helped some folks. The B6 you can take while pregnant (but check with your doc to be sure) but the licorice root should NOT be taken if you are pregnant or nursing.
Therapy CAN help, but the first step is really to let the swelling go down. This can take a couple of weeks.
Also, your doc may check your thyroid levels. CTS is a symptom of Hypothyroidism. Initially, when I went to the doc for CTS he checked my thyroid. And we discovered I am hypothyroid. Taking the meds really helped my left hand (two years ago).
Ergonomic work stations (for computer users) and ergonomic tools around the house can also help ease the pain. Even some things for arthritis sufferers (like bigger handles on can openers, etc.) can help with CTS too.
The "definitive" test for CTS is an EMG nerve conduction test. It does involve needles, but it's not too bad. It feels weird, and afterwards your arm will kinda hurt worse for a day or two. But, as C.Ann said, if you don't get some treatment, there can be permanent nerve damage.
Now, I'm not a doctor...but having talked extensively to my doctors and knowing what has worked for me and lots of other folks (I co-host a Carpal Tunnel message board) I've learned ALOT over the past two years. If you have any questions about the tests, or vitamins, treatments, splints, or anything else, I can provide you with lots of links to information!
Hope that helps!