What Is The Reason For Burning Sensation In The Wrist?

When my left wrist is not elevated then the veins in my wrist burn. Also if I have my wrist held at chest length for to long(4-5min) I start to lose feeling in my thumb and if I bend my elbow for to long(3min) then my elbow starts to feel weird. If I my arm is straight then I lose feeling in all my fingers and my wrist hurts. If I have my arm straight down than only my wrist hurts, like something in my wrist is stopping the blood flow. I am currently taking the flintstones vitamins once a day and potassium gluconate dietary supplement every other day. Age:17;Height:5.5;weight:199.6pounds I am not allergic to anything that I know of. My pediatrician put me on a diet and I have lost over 30 pounds in the last 4 months through diet and exercise.I broke my left wrist in 2007 and had to were a cast. My only other major injury was a head injury on 03/20/06. My blood work from 4 months ago said I was low risk for everything.