If you become unable to make your own health care decisions, your agent will have legal authority to make health care decisions for you.  Your agent must make decisions that are consistent with any instructions you have written in the Advance Health Care Directive form or otherwise made known to your agent.  Physicians and other health care professionals will look to your agent for decisions rather than your next of kin or any other person.

If you have not made your wishes known, your agent has broad powers to decide what is in your best interests, considering your personal values to the extent they are known.  Your agent can under no circumstances, however, authorize certain procedures specified by statute, including, convulsive treatment, psychosurgery, sterilization, abortion, or placement in a mental health treatment facility.

Some of the specific powers which can be given (or denied) to your agent in the Advance Health Care Directive are the power to terminate life support, and the powers, after you die, to make organ donations, authorize an autopsy and direct the disposition of your remains.