There is a class of documents sometimes described as Advance Health Care Directives, Advance Directives, Living Wills, Medical Proxies, Health Care Proxies, and documents bearing similar names.
All to often people become fixated on what will happen to their assets upon their demise and ignore taking care of themselves while they are alive. Essentially the purpose of these documents are to direct what course of action is to be followed in the event for what ever reason they can no longer make health decisions for themselves.
Generally, they fall into three categories, (1) direction(s) and expression(s) to all concerned parties with their medical treatment as to what treatment is to be rendered or withheld, (2) A direction and authorization empowering a third party to act on there behalf or (3) an integration and combination of both.
Needless to say that when a person is not longer capable in making their own health decisions, third party conflicting opinions abound. The utilization of these types of documents carries out the exact wishes and desires of the person involved. It avoids disharmony, disputes and discord between caretakers.