harden

I picked up my mother from Hospital today. When I picked her up she was feeling quite well, but her medication (esp. painkillers) has been raised.
During lunch she fell asleep a couple of times and she was talking nonsense.
There are two things I wonder about right now:
a. Why has her medication been raised? Last weekend she was feeling very well. We even took a two mile walk around the hospital. Right now she cant even walk around the house.
b. How long will she stay at home this time?

EDIT: My mother is still at home after 24 hours. She can barely walk and talks to my grandmother who died 7 years ago sometimes. I just talked to my father over the phone for about an hour and, needless to say, and he is very anxious.