It can happen while you're cycling, driving a car, speaking on the phone or working at a computer. It can also wake you up at night: Your fingers tingle or go numb, and they, your hand or wrist may ache. While it's normal for your hand to "fall asleep" on occasion, frequent such occurrences can be a sign of carpal tunnel syndrome (CTS). Here are three questions and their answers regarding this common nerve disorder: What's carpal tunnel syndrome? The carpal tunnel is a narrow passageway on the palm side of the wrist, bound by the carpal bones and traversed by nine flexor tendons and the median...