HIPPA doesn't really protect patients all that much. Anybody with a computer and some hacking skills can get into hospital and insurance records and find anything they want.
HIPPA protects HCPs from being sued, and insurance companies from having to cover things at times. I have a HIPPA contract for my clients, and honestly, it's to protect ME. Basically, my HIPPA contract includes nicely worded things like "If you do something like forget to feed your baby, or let your kid dehydrate and you then refuse to get immediate medical care, or lie to me about how or what you are feeding, it's not my fault when things fuck up. You just agreed to that." But, it sounds all legal (which it is) and nicer. But that is what HIPPA is for, HCPs and insurance companies, it does less for patients than was done for them before HIPPA.
I don't share patients' information with anyone but their doctor, but what the doc does with the info once he gets it is anyone's guess. Once your stuff gets into the system, virtually anybody can see it. I've gotten other people's data all the time, and it's easier to get than before HIPPA and electronic record keeping.
I would be honest....to a point.
I would NEVER tell a doctor if you even occasionally use recreational drugs. A "high risk" red flag may be put on your chart, and if you, for any reason, need a controlled substance for even the most severe pain, it will probably be denied you. I've seen it happen more times than I can count. Doctors are pretty conservative people, and the female docs are worse, when it comes to judging you than the men.
Give me a nice male doctor in his 50s or 60s, (Jewish is good, but other is OK, too) who likes me, I can relate to and don't feel I need to bare my soul to about every little thing, but can be honest about the stuff that IS his business, and I'm a happy patient. I do like to get my GYNs young, so I can train them.