In poetry, as in most creative writing forms, general words should be replaced with concrete images for a better end result.
Pain is general and means different things to different people.
I stepped on broken glass is a concrete image describing pain without much deviation.
Smell is general with deviations of interpretation depending on the individual.
Odor is more specific with a negative connotation but still vague.
Concrete images for bad smells or odors might be putrid fish or wet dog.
Basically, using specific or detailed images is considered more desirable than vague generic words. The only exception in creative writing is song writing. Don’t ask me why, but it is perfectly fine to sing about love without being very detailed.