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 Virginia, the determination of death is governed by state statutes that align with the medical and ethical standards commonly accepted. Under Virginia law, a person is legally declared dead when there is an irreversible cessation of all brain functions, according to ordinary medical standards, even if artificial life support is maintaining other bodily functions. This is known as brain death. Additionally, a person can be declared dead when there is an irreversible cessation of circulatory and respiratory functions. The pronouncement of death must be made by a licensed physician. It's important to note that while the pronouncement of death establishes that a person has died, it does not determine the legal cause, manner, or exact time of death. These aspects are typically determined through a death investigation or autopsy when necessary.