I used to get that a couple years ago. It feels like your f**king arms are going to break in half. I don't know what it is from, but I just kept lifting through it and eventually it went away.
Never stop lifting, even if it means lifting light!
This is a VERY common problem; it has to do with the tendons that run up and down your forearms. It usually happens when your palms are facing up and you’re curling a weight that your wrists can’t handle. For now I’d suggest to drop any exercise that irritates the tendons. I had this exact same problem and I beat it by replacing preacher curls with standing ez bars and replacing dumbbell curls with hammer curls. I also began to concentrate on how my wrists were during exercises; when I benched I made sure they were strait and not bending backwards etc…
Please Scroll Down to See Forums Below 
