As a student, you lead a busy life with no time to be sick. And if you do get ill, your ability to do well in school may be compromised depending on the length and severity of your illness.
If you are ill, you can still do a lot to stay on top of your studies. Here are recommendations.
As soon as you realize you will miss a class or lab, notify your professor or Graduate Student Instructor (GSI).
Check the syllabus on C-Tools to be sure you know what is expected.
Contact a classmate and ask to make a copy of his/her notes for your review.
If you're lagging behind, contact your professor or GSI. Email or visit during office hours and explain what's happening, to the degree you feel comfortable doing so.
Consider asking for an extension for any projects you are unable to complete on time.
Ask your academic advisor's advice about keeping up. If you're not sure who your academic advisor is, you can see Academic Advising.
About medical excuses: UHS can provide a "Visit Verification /Medical Statement," which most UM instructors accept. If you must drop a class for medical reasons, we may be able to provide documentation.
And most importantly, take good care of yourself – getting enough rest (see Sleep) and eating well are key to recovery and academic success.