Deadlifts don't hurt your back. The way you deadlift hurts your back.
Quite often, I find novice trainees don't understand how to build upper back tension when deadlifting, which can lead to issues down the road. An easy way to teach proper tension is through teaching individuals how to avoid shrugging. In the video below, I break down my favorite verbal and kinesthetic cues to engage the upper back prior to pulling heavy weight.