Why do my hands/wrists and forearms hurt from running?

i go to the gym daily, but whenever i run (treadmill) for 2 or more days in a row, my hands and wrists really hurt to move at all. it also effects my forearms but less so. When i stop running for a few days and just do other things there, i don't hurt at all the following day. I was just wondering what could be causing this.