So I just got back into it after a 6 month hiatus due to work. Now, other than being incredibly weak, when I go to do back squats my spine hurts while squatting. It doesn't really hurt after at all, just when I am in the motion of squatting. The pain is right below the middle of my spine and it seems to get a little better during my workout. The thing I am worried about is if it is hurting now when I am barely doing any weight, could this be a symptom of a serious issue?

Any thoughts?