Living Will, Generally
A living will is a legal document that instructs health care providers to withhold life-sustaining treatment if the principal becomes incompetent and has an end-stage medical condition or is permanently unconscious.

A living will can also provide the principal's personal preferences about receiving specific types of medical treatment, such as chemotherapy or CPR.  The principal also has the option of nominating a health care representative to interact with health care providers and make health care decisions on behalf of the principal if the living will becomes effective.

None of the instructions made by a living will can be followed until a health care provider documents the principal has one of the conditions stated above.  Prior to this diagnosis, a living will cannot be used to withhold any medical treatment and the nominated health care representative, if any, does not have any authority to act.

See: Living Will, When Effective; Living Will, Who May Create; Living Will, Delivery