My Mom wound up in the hospital for about a week, then a precautionary period in a physical rehab facility for a few days.  Fortunately, she's bouncing back nicely, though she's still a little unsteady on her feet.
Fortunately, it want anything truly serious: it was a combination of about 7-8 minor things happening all at once that just whammied her: high BP, high blood sugar, dehydration, fever, 3 unrelated infections- you get the picture.  She had no recollection of the morning I had to call EMS to take her to the ER...
Other than THAT, pretty boring, fortunately.