I had a tatto on my lower back. It didn't really hurt me whilst it was being done, except that the palms of my hands were sweating like mad and i was sleeping on the floor for a week. (that's how much stress i put on myself)
Pain is almost impossible to measure as everyone has a different threshold! I have 14 Tattoos, all had a different level of discomfort but worth it to me. Make sure you visit a reputable tattooist and make sure the design is well thought of as it is there for LIFE