If you eat lethal poison, you will die no matter how much you think about it trying to make yourself not die.
Same with an environmentally induced chemical problem in the body.
It was your mental decision to eat lethal poison.
An environmentally induced chemical problem (and the lethal poison) wouldn't be a problem if you didn't mentally identify dying or the physical consequences as a problem. A problem is defined by a subject. If a subject doesn't define it as a problem, it's not a problem.