16yo had tingly feeling and elbow pain last year once he grew to 6' and started trying to throw harder. Nothing structurally wrong, but he has had to learn to throw all over again. At this point he is able to throw without pain, with the same or better velo, but his accuracy and finer points of pitching are still a work in progress with his new motion.
I am not a doctor, but my wife is. While she understood the diagnosis far better than a lay person, she would emphasize that orthopedics(or whatever specialty pitching injuries see) are not her specialty, and that seeing a competent specialist who understands arms, and pitchers, is necessary. In out case we had a fantastic PT guy, who was a trainer for Team USA baseball, and treated pro pitchers also.
Seems to me that Leftymagic has the right of it...but what do I know, I'm just some guy on the internet.