You should have it looked at. It could be a pinched nerve that is causing it to go numb. If it is numb then the "pinch" is pretty severe and that is why you need to get it looked at.
Lots of things can cause feelings of numbness in the hands. It's often pretty minor. Not to be alarmist, but carpal tunnel is a likely culprit. If it doesn't improve with rest, you should try to have it checked out, because in addition to pinched nerve, there are serious diseases (Parkinsons, MS) that can manifest with this symptom.
Definitely consider your computer and cell-phone usage. It's quite possible that you'd benefit from an ergonomic keyboard or cutting back on texting.
Carpal tunnel possibly ??? if it begins to move up hand to arm and is painful i'd worry but if not it could be just typing or your career..