Difference Between Impede and Hurt

How do you determine if you are impeding yourself or hurting yourself with a trait? Do you just choose which you’d rather do, mechanically? Is it based on how bad you describe what you are doing? The examples I read in the book didn’t seem that far apart as far as how severe they sounded. Also, one being -1D to you and the other being +2D to the opponent makes it seem like you are messing up yourself in impede and helping the enemy in hurt. But I figure you can justify it either way “I’m angry, which messes me up” vs “I’m angry, which helps my enemy”.

It’s mostly about what you’re willing to risk on the roll. Once you decide that, you give a description appropriate to the level of pain you’re inflicting.