I know I need to back off and accept that for medical matters he is treated as an adult, but can't help freaking out and imagining all sorts. DS (17) received letter this morning marked Private and Confidential. Was obviously a health related matter from the postmark and the fact that the start of his NHS showed through the window of the envelope. He got home from school and took it upstairs - I then in passing asked what it was and he told me it was from a university. Clearly not true due to the postmark (wrong town) - I said don't be daft, that's not the case and now he is very defensive. He admits it is health related but says there is nothing to worry about and that he doesn't want/need to tell me what it is. Of course, I am worried and imagining all sorts. He did say he doesn't have an STI - but added that the letter wasn't about that anyway and that it was just routine unsolicited information. Is this likely for a 17 year old? he hates injections so I am a bit concerned it may be about a vaccination and he isn't going to have it - his choice I know, but it would be helpful to discuss it with him. Anyone any idea what it might be about?