Two ways that stress could negatively impact a students performance is by causing them to procrastinate. When you're stressed, you tend to keep putting things off because you "just can't deal with it" at the moment. This could cause the student to turn in their assignments late (or not at all) and cause their grades to drop. Additionally, when you're stressed, it's harder to fall asleep, and once you are, you don't sleep as well. Sleep deprivation can greatly affect a student's in class performance by causing them to fall asleep in class, or not pay attention as well.
those are all physical changes and most physical changes can be undone like crushing a pice of metal you can flatten it back out you anwser is physical change
