Rule 511 Waiver of privilege by voluntary disclosure.

If you have a legal privilege that lets you keep certain information private, like conversations with your lawyer or doctor, you can lose that protection by sharing the information yourself. Once you or someone before you who held that privilege voluntarily tells others about a meaningful part of what was supposed to be confidential, you give up your right to keep it secret going forward.

This means you need to be careful about who you talk to about private matters covered by a privilege. If you tell a friend, post about it, or bring it up in an unprotected setting, you may not be able to stop that information from coming out later in court, even if it started as a protected conversation.

There is one exception. If the way you shared the information was itself protected by another privilege, you do not lose your original protection. For example, if you talk to your lawyer about something your doctor told you, that conversation with your lawyer is still privileged, so telling your lawyer does not count as giving up your medical privacy protection.