Does my mom have a mental illness?

I think my mom has a mental illness, but I am not sure what. She accuses people of stealing her belongings all the time and ends up finding them herself. She doesn’t apologize about it. She would stay up all night looking for things that aren’t in the house But she is convinced it’s hidden and trashes the room to try to find it. She is paranoid and thinks everyone is out to get her. She wasn’t always like this. I don’t know when she started acting this way. How can I help my mom?