The determination and pronouncement of when a person has died has medical, ethical, and legal implications. Laws vary from state to state, and death is usually defined in a state’s statutes.

Definitions and terminology may vary from state to state but generally a person is dead when, according to ordinary standards of medical practice, there is irreversible cessation of the person's spontaneous respiratory and circulatory functions. If artificial means of support preclude a determination that a person's spontaneous respiratory and circulatory functions have ceased, the person is dead when, in the announced opinion of a physician, according to ordinary standards of medical practice, there is irreversible cessation of all spontaneous brain function.

Death occurs when the relevant functions cease. But a formal pronouncement of death is not a legal determination of the cause, manner, or time of death.

In Arkansas, the determination of death is governed by state statutes which align with the general medical and legal standards for defining death. According to Arkansas Code Annotated § 20-17-101, a person is legally dead when there is an irreversible cessation of circulatory and respiratory functions, or when there is an irreversible cessation of all functions of the entire brain, including the brain stem. This determination must be made in accordance with accepted medical standards. The use of artificial means of support may necessitate the latter definition, focusing on brain function, to declare death. It is important to note that while a physician can pronounce death, this pronouncement does not establish the legal cause, manner, or exact time of death; those determinations are typically made by a coroner or medical examiner through further investigation.