What Is the Medical Definition of Death?


Michael Sabom

Article ID:



Apr 13, 2023


Apr 16, 2009


According to the “whole brain” definition of death, life ends with the “cessation of all functions of the entire brain.”9 During her first surgery, Pam’s brain had been drained of blood and found “dead” by all clinical tests of brain function. According to Spetzler, “If you would examine that patient from a clinical perspective during that hour [of hypothermic cardiac arrest], that patient would by all definition be dead.”10

Addressing the question of when death begins, Harvard internist Linda Emanuel writes:

The reigning view [of death] has assumed that life and death are nonoverlapping, dichotomous states. This view acknowledges that dying may take time, but presumes that a threshold event is nevertheless definable; a person is thought to be either alive or dead, not both.…Is there an event that can identify final and complete loss of life? The answer appears to be no.…The process of dying occurs at different levels of organization, from the organism to the organ, cellular, and subcellular levels, and each set of systems can decline on a somewhat independent trajectory.11

Scientific observations support Emanuel’s contention. Ten “brain dead” organ donors demonstrated significant changes in blood pressure and heart rate in response to the harvesting of their organs — reactions only possible with portions of the brain intact.12 In nonhuman vertebrates, moreover, “suspended animation” (i.e., complete cessation of all microscopically observable cell motility and division) has been induced and then reversed after prolonged periods of oxygen deprivation.13

Death is a process — it does not occur at a single moment in time. The determination of death rests on the premise of reversibility: if the person recovers, then by this convention that person never was dead, regardless of the absence of vital signs or brain function. Doctors do not resurrect their patients; rather, they resuscitate them. Based on this definition, Pam encountered a near-death experience, not an after-death experience.

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