What Causes Joint Pain In The Fingers, Wrists, Arms And Knees?

Good evening. I'm a 19-year old who's just very worried about whether I'm really sick or not. I've recently been checked and I have elevated ESR, WBC and Eosinophils. Also, I've been experiencing joint pain in my fingers, wrists, arms and knees. I was wondering what could this actually mean? Thank you.