Like everyone else, I recommend that you see a doctor.

I had a very bad problem a few years ago with carpal tunnel syndrome. Saw a doctor, who prescribed a wrist brace and gave me a bunch of information about CTS and the various medical approaches to dealing with it. Surgery is an option, but it can do some damage and won't necessarily completely fix the problem. Mainly, if you're going to do it, you need to combine it with some behavior modification to avoid re-creating the problem after surgery.

In my case I got past this problem primarily by analyzing my playing and making some changes. At the time I was playing out 4-6 times a month with a rock and roll band, playing electric lead guitar. I slung it kind of low because that's how my right hand liked it, but I didn't realize that it was giving me problems in my left, because I had to bend the wrist at almost a 90 degree angle to situate my fingers over the strings (being a classical guitarist originally, I'm not one of those "thumb over the top" guys). Constantly working my fingers with my wrist in such a contorted position was primarily what caused my problem. The solution was to shorten my strap (elevating the neck and allowing me to straighten out my wrist), and get back to a more ergonomically correct playing posture. All that classical guitar emphasis on hand positions exists for a reason! The problem began to fade when I made this change.

As you might expect, once something is aggravated (like the tendons that run through the carpal tunnel) to the point where it starts to get inflamed, there are a lot of things that can keep it aggravated. Sleeping with your wrists cocked forward is an aggravating factor -- the doctor I saw told me that this is very common for some reason. I got into the habit of deliberatly laying my wrists out straight when I went to bed, and even when I was asleep there was a part of my brain that stayed conscious and reminded me not to cock my wrists. Other everyday things -- typing, driving, etc. -- can also aggravate this type of injury. If you're conscious of these things, you will start to notice what you're doing, and take steps to correct them -- adjust your grip on the steering wheel, relax your wrists when you type, etc.

I don't know if any of this actually applies to your situation or not, but figured I'd pass my experiences along. Good luck.