Do I and how do I explain to Mom that she has dementia?

I've been trying for 2 yrs to get help for my mom. In my experience you can't convince her she has it. I'm going to try some new angles I got right here on this site. My mom also is mean & unreasonable. I even tricked her into a cat scan & it was normal! I'm trying geriatric psychiatrist next. But, I will have to trick her again. Luck to both of us

Thank you for your help but no UTI we already checked. She was aggressive at the doctors office for her last appointment so we got that covered too, but thanks anyway.

Sorry, it would be almost impossible to explain to a person who has dementia that they have said disease. Even if the brain loops around for a clear moment, why tell one's parent that they have that?

If your Mom is being mean and aggressive, make an appointment for her to see her primary doctor to run a test for an urinary tract infection [UTI] as those are definite symptoms of the infection in the elderly [young people don't get those symptoms]. At least you would know if it is dementia causing the symptoms or if it is UTI.