A friend on Facebook recently asked the question: “Why do I always get sick around finals?”. I had to get a comprehensive answer for her. And now that I’ve done that, I have to share it with you.
This is actually a well replicated finding. It appears that times of stress, such as exams specifically, affect immune functioning (check out this study of cytokines in healthy medical students during exams). Stress is known to affect immune functioning. We’ve known for quite some time that this is true in humans, and even in other animals like salmon (!). In particular, we know that levels of the hormone cortisol increase during stress, and that this increase in cortisol during stress is related to the immune system being less able to resist disease (refer to those poor stressed out salmon mentioned above). Cortisol is immuno-suppressive. And if you haven’t been sleeping well during exam time, that could just be adding to the problem, because sleep deprivation is also correlated with immune system deficiencies. (But don’t worry too much, if the sleep deprivation is short-term, so are the immune deficiencies).