Mom was diagnosed and treated for UTI. She has never been diagnosed with dementia, although we know she does get a little confused here and there. She always has symptoms of "sun downers" if she stays over in the hospital. Upon her return home, it has always gone away. This time it's different. It's almost like she is delirious. She started improving several days after returning home, and had a couple of "normal" days but all of a sudden, this morning it's like the switch has been turned on again to the confused state of mind.
The last time with Dad after a fall, he thought he was in a hotel and wanted to go downstairs to pay the bill. After 48 hours at home he was getting back to normal.
For my Mom, it was like that light switch, each new day we didn't know what to expect.