Should I tell her (98, no memory) she has dementia? She is so confused. Last night she just sat and looked at me. I don't know anything.

If she can't remember where to sleep, your grandmother is not going to remember you telling her she has dementia.  I know the repeating is draining sometimes, but it is part of the disease.  I just keep telling my mom that she is in a beautiful apartment (shared memory care room) she is safe and she is close by so that I can get to her quickly if need be.  That seems to settle her on those days where she is super confused and on repeat.

Just reassure her everything is ok and keep telling her where to sleep and where to go to the bathroom.

I posted but can't find it so I will post quickly. My 96 year old mother died. I took care of her. She was back and forth from hospitals but doctors said there was nothing wrong with her but getting old. She was not on any meds. Her body was getting old and there is no cure for that. Taking her home from a hospital stay of 1 day she was in great pain. I asked the doctors and they said if they gave her any pain meds she would probably stop breathing. So I was told to make a choice. I did. No one deserves to have pain meds held back because they are old but healthy. We all agreed she needed the minimum amount she could handle. As we were getting on ambulance home, she found strength to scream 'kill me, please kill me'. The doctor and I agreed to give her the minimum amount needed and she was able to tolerate the ride home. At home her breathing slowed and she entered the last stage of breathing signaling us she was close to death. Braxton hicks.
My brothers barely made it from the next room in time for us to all hold her hand and tell her to let go, we loved her. She died in peace. I am telling you this because of your grandmothers age and health. Don't be taken back by surprise if this happens to you but be ready. She us old, not sick, and her issues are different then people who are sick. Just thought.

why did she move in with you, why not her own daughter or son? do you know any of her own personal history? sounds like someone just passed her onto you. not making any bad accusations, but are you still working? do you have a family of your own? has she been diagnosed with anything? Sorry I can't think of anything else to offer, i wish you luck.

i agree, do not say the word dementia! To me its offensive and implies "crzy" I hate that word and saw it too many times. Rephrase it to "memory loss imo My Mom is 92 home hospice pending Nursing Home and cannot stand. I'm disabled and unable to keep the house going . Cherish each second with her- things change fast! tc, prayers!

No, you shouldn't tell her she has dementia. What good can come of that?
If she doesn't remember who you are or where she is it would be ok to tell her who you are and that she's in your house.
You'll have to repeat yourself over and over, but it might make her happy and be a comfort to her.

She won’t remember you told her. I moved in with my grandmother with dementia and it has been hell! There are times I just get in my car and leave because it gets to be too much. She acts just like a stubborn child if she doesn’t get her way