Corrupt Project File opens - How to Know if it is Damaged

I’ve gotten the Project File corrupted, can’t be saved issue before, and just got it again for a few projects. I can reopen the file on simply restarting my computer, and it always seems to work fine. Recently I’ve gotten paranoid though. The Project file will be a lot smaller, like a fifth the size that it was in a previous version. What does this mean? Is there something lost even if it seems okay? I often keep working from the reopened file, but now I’m concerned there is something I am missing. How do you know if there is any damage to the Project file? Thanks a lot for any replies!