How sleepy does an elderly person need to be before they have to be referred to a full time care facility?

You can keep them home forever, its your decision, they never "have" to leave. My Mom has good mornings, then sleeps of and on all afternoon, then a puree supper and a change of diapers and back to bed around 8ish. She is incontinent, cannot understand or see, nor can she walk, but she knows she is surrounded my many songs and kisses here and I rub her hair and face to remind her. Please dont let people tell you when is the time, it is your decision. I was told by her Dr that once in a NH they go straight downhill. The key is "what would you want if you were in her shoes." No doubt its hard, but to me, its just what we do.

Really, it's more about what waking hours are like. I know someone who has slept for probably 20 hours a day for over a year. Her 'waking' hours are really more like dozing hours (at this point, I think it's just a deep-seated fear of death that keeps her going). She's never fully awake. I also know someone else who sleeps nearly that much, but when awake participates in life; eating, interacting with others, watching TV. So, it's very individual. I don't think anyone who is sleeping away most of the day should live alone. But, if there are no significant care issues, they could probably be taken care of at home if someone is in the house all day. Personally, I think an AL would be the best environment.

By sleepy, you mean just wanting to sleep all the time? Dementia patients usually sleep alot, but also infections can cause a change in sleep patterns. My mom had UTI infections that would also cause increased sleepiness. Without more info, I would just suggest taking her to her primary care physician and consult with them.