Hi, and welcome to the community!
First off, I think it's wise that you reached out. Secondly, I can't really diagnose you, for your safety. That said, there are a few causes of large knuckles and most of those causes are not a big deal and it's more of a cosmetic issue. You didn't mention any other issues, like pain or stiffness. Are you experiencing anything like that?
Best, Erin, Team Member.