A healthcare agent becomes active if you lose the ability to understand the medical problem and the risks and benefits of medical treatment choices. Put another way, if you lose the ability to make and communicate choices that show you understand and appreciate the decisions being made and their possible consequences, or if a court declares that you are incompetent, then the healthcare agent steps in. You often hear the term "incapacitated."  In medical situations, if you become incapacitated, that means doctors have determined that you have become unfit or unable to make and communicate medical treatment decisions, and the healthcare agent will need to decide on your behalf.