help! Goldfish with red scale?

Hello! I own 3 fish but I had a question regarding my male goldfish. He will get these lifted red scales every couple weeks and I’m concerned it might cause him discomfort? Is this the normal scale shedding process. It appears lifted & red & buldges out from his side a little. It will typically resolve itself in a couple of days & doesn’t change his behavior at all. Has anyone experienced this or have any advice if there’s something different I should be doing? Could this be damage from rubbing up against the plants in his tank as well?