Ill be just sitting there in class with my arm rested(riught arm) and it will start to feel numb on the right side of my hand and then a numbing feeling will begin to start from there and goes up all the way to my elbow and my whole arm feels numb in a matter of seconds. Is this CTS or tendonitis? Its been bothering me for more than 2 years now, and I just like 2 months ago have been an avid keyboard user, so I know that this could not be what triggered it. What is going on with my arm?