Advice about a possible fish disease?

My goldfish has rough-looking bumps on top of his head. I will try and post a picture later but maybe someone might have an idea of what it is without one. He doesn't have a clamped fin, he eats very well and swims around like my other fish. I just want to make sure that nothing is wrong. The bumps are not large. It kind of looks like callouses have developed. They have been there for a while but they haven't gotten worse and his behavior hasn't changed or anything. I'm thinking that if it was something serious then I would have been able to tell by now but I still would like to make sure. Thanks for any help in advance!