My wife's grandpa, over 80, got hospitalized a couple of weeks ago due to hyponatremia. As this problem implies, it was probably a result of various other illnesses he has been suffering from lately. While at the hospital, he catched pneumonia and above all he got a very violent bacteria, which reached his heart and even harmed his artificial pacemaker. The only way to save his is surgery, to remove the pacemaker, but his condition is so bad that they're currently trying to figure out how to do it, and in any case the chances of success are very slim.
Had he stayed at home, eaten better and drink a lot, he'd probably had gotten rid of the problem in a few days.
And that, ladies and gentlemen, happened in one of Israel's finest hospitals (Rambam).