Noe Chrobot
Noe Chrobot voted up Angela Anthony's answer

Well, the main reason would be that your skin and vein are being pierced by a needle and a long piece of plastic is being threaded into your vein. Now if you're nice to your nurse, she may use a smaller gauge of needle, if you're a pain....you're getting the biggest one available!....jk.

Seriously, a lot … Read more