Stress = Innumerable potential diseases
You thought stress was a problem for your health? Well, that's an understatement.
Among other effects, stress even dumbs us down from a physiological perspective.
And it seems it makes us vulnerable in front of the myriad diseases we already carry in a latent form. It's the same pattern followed by our mind, in a way: if you're not mindful about what you're thinking at the moment, you might be overwhelmed by dark thoughts.
So, there is an immune system in place for both our minds and bodies that we need to maintain at acceptable rates in order to function normally.