I think I have carpal tunnel. How can I know for sure?

Carpal tunnel answer. http://www.handctr.com/carpal-tunnel-syndrome-q-a.html median nerve compression at the wrist gives numbness in the blue area and loss of muscle function in the large muscle of the thumb here is a nice video i made a few years back http://www.Youtube.Com/watch?V=lwghddhvm60&list=plcbd41f7a42e20469&index=4&feature=plpp_video.
See your doctor. He/she will listen to you, perform an examination and possibly run some tests to find out if you have carpal tunnel.