Cortisol effect on immune system?

[otacon]

I'm currently researching the effects of cortisol on the body in relation to the 'fight or flight' response and I read that cortisol suppresses the immune system.

How would this be a benefit to a human in a dangerous situation?

Surely if you were at risk of being harmed, you would want to stimulate the immune system in case you were wounded and needed to fight infection.

Have I misunderstood something here?

[canalon]

Short term advantage trumps long term one. If you die because you cannot react adequately fast enough, there will be no point of having an immune system, depressed or not. So the side effect of the fight or flight reaction is not countered selected strongly enough to matter the massive selection for that response.

Or if you want in other word: I do not care if my cancer treatment make me lose my hairs if it allows me to survive. I would be much less forgiving if it was the consequence of taking an Over-the-counter painkiller...

[otacon]

Thanks, great answer! all makes sense now .

[aptitude]

Yeah, and the main reason why cortisol suppresses the immune system is mainly to reduce inflammation.