Question
sir, how long do you have to go to school to be professionally certified to be a chiropractor? what was your most challenging class? thank you for your time.  

Answer
i believe there is an associate in science prerequisite (2yrs), then chiropractic college which is a four year program. most challenging for me was probably dissection, barfing (literally- no, just kidding) back all the vascular and neuroanatomy stuff on exams.