I have small red bumps. that keep popping up, on my back, only. they hurt to the touch. but i can't pop or burst them. can someone tell me, what that is? thanks..?

These bumps would have to be inspected by a physician or dermatologist for accurate diagnosis but could be a form of acne or ingrown hairs.or irritated hair follicles.

Try a google search which will show you hundreds of red bumps (not a medical term, therefore not diagnostic). What would be infinitely more accurate would be to actually go see someone with multiple tens of thousands of hours of training and a lifetime of practical experience. You should have a GP with all of your baseline data. If not, find one, or go to Urgent Care (not ER), or Dermatologist.