masturbate frequently so that your wrist gets used to fluid motion......I suggest switching it up if you can manage that.
http://familydoctor.org/023.xml
TECHNICALLY of course it is possible to have carpal tunnel or even arthritis at a young age, but I seriously doubt you have that. Most kids simply play too many games without resting or moving the hand in different directions and such then build it up in their mind that something is wrong with em.
Stop playing FPS for hours lol. Problem solved.
I play pianio, guitar, type about 100wpm, my job is internet related, also played trumpet and violin.....I definitely see carpal tunnel or arthritis in my hands and fingers as an adult
As of right now if I play fast on my guitar for long periods of time the thick muscle in the thumb starts to tense up and hurt =/ Annoys me too