It shouldn't matter to me that college students take sick leave, because people who eat whole grains will inevitably have headaches and brain fever, and it is normal to take sick leave occasionally.

Generally speaking, if you take time off, you won't deduct any credits. If you need to ask for leave due to physical discomfort, you should see a doctor, write a sick note and ask for leave from the counselor. Asking for leave requires the consent of the counselor and the school.