What Causes Carpal Tunnel?

My Right Wrist Hurts From When I Fell Into The Fireplace And Cut it, Umm that was like 2 years ago.. Now like when Im resting my arm on something for moe then 10 minuets it hurts.. I went to the doctor and she tapped my wrist but she never said what it was. But she gave me this like arm wrap, And Some Purple Silly Putty.. Could This Be Carpal Tunnel.