The aim of this paper is to deal comprehensively with various ethical issues concerning advance directives. Advance directives are oral or written statements which declare whether a person wants to receive life-sustaining treatment, in the event that they lose their decision-making capacity. There are two types of advance directives: the first is an instructional directive which identifies situations in which the patient would want specified treatments. The second type is a proxy directive, which allows the patient to designate someone to make decisions on their behalf. Advance directives are recognized in some form by the laws of every state. Despite the fact that advance directives have been available for more than twenty years, few adults have completed any type of advance directive document. In order to explore the cause of these law numbers, I survey relevant federal and California legislation and considered the legal issues surrounding advance directives. Then I consider the ethical arguments concerning advance directives. First, I discuss the ethical issues of advance directives in terms of the principle of autonomy and the doctrine of informed consent. Second, I discuss the conceptual problems of advance directives, which are rooted in the principle of autonomy. Finally, I reconsidered "the principle of autonomy" underlying advance directives.
