Are there any laws protecting a private citizen from someone posted information about their health?

[198]

No law against this, unless they're a healthcare professional and you were in their care.

If they're a private individual, who knows this, no crime.

[D J]

It depends on who does the posting. Medical professions are covered by the HIPA laws, others are not.
So if a clerk in the doctor's office posts something on line they have broken the law. If your friends does it after you told them something is confidence, they have not broken the law.

[Eliot K]

No. Private medical records are protected by law.

[Neon]

Most of what has been answered already. If it's your brother - then no. However, you CAN take him to court for Defamation of Character, especially if what he is saying is lies, and you have documented proof that he is attacking your character in ways that are not true.

Largely, because it can cause psychological injury, and/or it can affect your career or future career plans. Such as, if he's telling people you have an STI or STD that you do not - and you don't get hired, or you are at risk of being attacked for it.

[Landlord]

It is legal for anyone to share unless they are your health care provider. Your doctor can't talk about your health situation, but your neighbor, friends, family members, even strangers can do all the gossiping they want, even on facebook.