The 1-10 scale is also to try to allow comparisons over time with your own pain. So "it was a 6, and now it's a 4" means one thing, where "it was a 6, and now it's an 8 to 9" means something else. Asking you to create a scale certainly isn't a panacea, but there is at least a hope of getting better comparisons than "Yes, it hurts. A lot. More than before? I don't know. It hurts enough now that I can't think about before." However, if I got you to give me a number earlier, I can write that down so you don't have to remember it.

It can also be used in treatment goals. "What level on the scale, for you, is annoying-but-bearable pain? Can we adjust your meds to get you at least to that point?" [Yes, ideally, we'd aim for no pain, but the side-effects of most of our analgesics make that impossible in many circumstances.]

At least when I was taught to use this scale, we were taught to define the end points for the patient (...where 0 is no pain and 10 is the worst pain you can imagine) and that the scale was completely subjective and the end points would be different for each patient.