If you’re over 18, it doesn’t matter if you’re not legally married, or are legally married or someone’s adult child, you must have a legal instrument designating someone other than yourself to get medical information about you and make medical decisions for you if you can’t do that yourself. This is called a Medical Power of Attorney or a Medical Directive.
A power of attorney is a legal document that appoints someone as your representative and gives that person the power to act on your behalf. With a medical power of attorney, you appoint someone – often referred to as your attorney-in-fact or your agent—to step in and make medical decisions for you if you can’t make those decisions on your own.