What would happen if i stopped having energy drinks?

I was wondering what would happen if i took a break from having energy drinks for a month (30 days) because i usually drink 3 in a week, and i know i'm suppose to have my blood work done once my birthday comes next month, and i just want healthy blood when it happens, heal myself up you know. But like would i get like really moody, or get lots of headaches, without having it? I've been drinking them for 3 years by the way, because of my friends drank em. And would i get jitters or whatever if i started drinking them again?