Why does my 94-year-old mother go to bed and then wake up a short time later thinking it's morning?

Thanks; she is in AL. I don't believes she even leaves the room. I will discuss with her doctor. Her mind is actually very good and there are no signs of dementia.

Is she still in AL as your profiles says? Is there some reason that the staff can't explain to her that she needs to return to bed? I might explore a bed alarm, that alerts when she gets up, so the staff can go attend to her before she gets dressed and have her return to bed. I'd also discuss it with her doctor. Sleep disorders are not uncommon with dementia. I'd explore if a light medication at bedtime would help her stay relaxed.