By the context of the conversation only, i think :) Norwegian are (usually) people of few (and effective) words. I find it that a lot of things can only be understood by knowing a bit more of the conversation -Which is a great incentive to "ask away" and practice your norwegian :D
Well, I think you may already know the difference between å kutte and å skjære - But in case you don't yet...
I've just read in another post that @Deliciæ wrote
When using a knife, "å skjære" would imply that the knife was either moved back and forth, like a sawing movement, or carving something. "Å kutte" refers to more of a chopping movement; cutting more or less straight down
I wouldn't say there are any issues with using that terminology in general, but I would be wary of labeling people as "selvskadere", for instance.
People will of course weigh their words around those struggling with self-harm, and it's a delicate subject either way you look at it, but Norwegians aren't a particularly squeamish people.