What is the hardest class you'll have to take in nursing school? Well, that depends on a lot of factors, such as your program, teacher, etc. However, for me, I'd have to say that pathophysiology was the hardest class I had to take in nursing school. We had to cover a TON of material in a very short time. The good news is that I learned how to study better, and it prepared me for the other tough nursing school classes I was about to take. Today, I actually LOVE learning and teaching patho!