Struggling Reader in HIGH SCHOOL? or Reading Disability?

In the literacy centered world that we live in, there is an approach to tag each student walking through our doors with a number that directly correlates to their "reading levels." There are two issues that strike a nerve for me in this process 1) Why label? and 2) Is the label overused or misused?

I want to specifically address the second topic. Why in the world is it that no one can answer my questions at the high school level? What is the difference between a "struggling reader" and a "reading disability?" Moreover, why are some students granted an IEP for this, and some are not? Dyslexia as a disability seems to be common; however; are "struggling readers" incorrectly put into this box? As a high school professional that deals mostly with "struggling readers" it is a difficult notion for me to work with students labelled as a "reading disability." A disability seems to be something that we can't resolve.

Are these labels misused? Are we incorrectly overusing them? Are the labels themselves hurting the students?