Turtle shell bump?

by Alison

My red-eared turtle is about 8 years old and one side of his shell has a large bump in it, is that normal? Like, it's bumpy all over, just there's like this large bump that's really noticeable on one side and my mother says it's fine, just the way it's growing, but she knows nothing about turtles. I just want to know if my turtle is ok.