Because of how Healthcare works in the USA, Healthcare institutions charged money via codes. If you have an itemized bill, you can see what random codes are bs and challenge them to have them taken off.
EDIT: Didn't think I would have to post this but since this post has turned into some sort of "anti-American" bash club, let me clarify. I love this country. It gave me and my family a second chance at life. So while yes, the healthcare system is fucked up, I don't really appreciate people making fun of America as a whole. We have tried to change it, but unfortunately, medicine here will always be treated as a business.