An advance health care directive, also known as living will, personal directive, advance directive, or advance decision, is a set of written instructions that a person gives that specify what actions should be taken for their health if they are no longer able to make decisions due to illness or incapacity. The instruction appoints someone, usually called an agent, to make such decisions on their behalf. A living will is one form of advance directive, leaving instructions for treatment. Another form authorizes a specific type of power of attorney or health care proxy, where someone is appointed by the individual to make decisions on their behalf when they are incapacitated. People may also have a combination of both. People are often encouraged to complete both documents to provide comprehensive guidance regarding their care.