A living will is a document that outlines specific medical instructions to be applied if you are alive but are unable to communicate your wishes for yourself. Unlike last wills, they have nothing to do with property division after your death. Rather, they state that you do (or do not) want artificial life support if either:
you become terminally ill and will die shortly without life support; or
you fall into an irreversible coma or persistent vegetative state.
A living will also lets you make decisions about whether or not you want to receive pain medication or artificial nutrition, and allows you to list other special instructions for your care. For example, some people may want to remain on life support only for a limited time period.