I think I might have to get surgery for a hernia, and was wondering if they will ask for a urine sample or take a blood sample or anything. Is this standard for operations?

If they happened to test me, and it showed up, does this "confidentiality" thing really hold up?? I mean- I'm 17 and obviously wouldn't want my parents to know, that would be terrible. Would they notify them?

any help would be great!