I Have Been Having Swollen Knuckles For Last Coupe Of

I have been having swollen knuckles for last coupe of weeks. I'm in high school and I write a bunch. It's normal after a write a lot that my knuckles get swollen and they hurt(throbbing). I put ice on it and it feels better. I'm wondering why this is happening and things that I can do to help it during the school day.