system
Given the following post, respond as if you're commenting on Reddit:
human
Is there any truth behind the idea that it's common to get sick soon after easing up after a long spell of strenuous work?

Let me explain more clearly. In the teaching profession a lot of people seem to think that teachers tend to get sick as soon as vacation rolls around. I think the idea that some people hold is that as soon as we let up it affects our immune system in some way - as if the immune system lets up as well (or something along those lines). Might there be some truth in this belief?
gpt
Stress, in the very short term, causes a release of adrenaline; in the longer term, it's cortisol. Cortisol suppresses the immune system; in fact, the reason that steroids like prednisolone work is that they're like cortisol. It in suppressing your immune system, it makes you susceptible to infection, but will mask a lot of the symptoms or allow you to push through it. As you de-stress, cortisol drops, the infections are still there but your immune system suddenly takes notice of them (most symptoms are caused by your immune response, not the infection itself). So you get sick.

Fun fact: there's a marsupial mouse, the males of which only see one mating season. For that period of 2 weeks, they're so hopped up on cortisol that they don't eat and barely sleep; they just have astonishing amounts of sex until they're basically disease-ridden sacks of bones and patchy fur (because of the immunosuppressant action and the fact that it helps mobilise fat stores). Then they keep going for a bit longer and drop dead.