easy to find veins, but which ones are safe?!

[nogills]

hey guys, swim has been using the same vein for a pretty long time now and it is just starting to look kinda bad and getting kind of hard to shoot in. swim is a pretty thin dude so he has a lot of visible veins in his arm. i know there are two kinds of veins...one that leads back to your heart or whatever, and one that like...goes to your hands and what not. i know swim doesnt want to shoot into the ones that go straight to his hands, so how does he tell the difference? which veins can he use ?!?! a friend told swim that if swim is using the left arm for injections, the vein LEFT of the main typical middle injecting vein (the one in the middle of the bend of your arm..you know) is a good one to use. like kind of if you roll your arm a little bit, its the vein right next to it to the left. know what im talkin about? but i dont know. swim just doesn't want to fuck his arm up or waste a shot because he shoots into the wrong damn vein. thanks for the help