A living will, despite its name, isn't at all like the Last Wills that people use to leave property at their death. A living will, which can also be called a directive to physicians or advance directive, is your legal document to tell your physicians your wishes for end-of-life medical care, in case you become unable to communicate your decisions. It has no power after death.
With that explanation in mind, one of the major differences between a will and a living will is the time they take effect. A Last Will and Testament has no legal authority until you've passed away, at which time it must be filed with a probate court. A living will, on the other hand, takes effect while you are still alive, but your health care situation has meet certain state requirements giving it authority. Generally, a living will does not go into effect until you are incapacitated, in Idaho, it is often because you're in a persistent vegetative state (brain dead) or your death is imminent, and you are incapable of communicating your end of life choice. Jeppesen Law recommends a living will as a useful way to avoid costly and time-consuming litigation among family members about your end-of-life treatment, if you don’t remember, please read about Ms. Terri Schiavo’s story.
The essential function of a living will is to provide instructions to your health care providers and express your preferences for treatment, which is why in some states it is referred to as an advanced healthcare directive. An advanced directive can signal whether you want to receive all possible life support treatment, including artificial respiration and intravenous feeding. Similarly, your living will can reflect the fact that you do not want to receive life support. You can also express preferences for or against other specific treatments and medical procedures.
Again, this is in sharp contrast to a regular “last will and testament,” which has no effect when the will-maker is alive but becomes legally binding at death.