Death

==Diagnosis==
[[File:All causes world map-Deaths per million persons-WHO2012.svg|thumb|upright=1.4|[[World Health Organization]] estimated number of deaths per million persons in 2012{{Div col|small=yes|colwidth=10em}}
{{legend|#ffff20|1.054–4.598}}{{legend|#ffe820|4.599–5.516}}{{legend|#ffd820|5.517–6.289}}{{legend|#ffc020|6.290–6.835}}{{legend|#ffa020|6.836–7.916}}{{legend|#ff9a20|7.917–8.728}}{{legend|#f08015|8.729–9.404}}{{legend|#e06815|9.405–10.433}}{{legend|#d85010|10.434–12.233}}{{legend|#d02010|12.234–17.141}}{{div col end}}]]

===Problems of definition===
{{Main|Medical definition of death}}

The concept of death is the key to human understanding of the phenomenon.<ref name="MohammadSamir">{{cite journal |author1=Samir Hossain Mohammad |author2=Gilbert Peter | year = 2010 | title = Concepts of Death: A key to our adjustment | journal = Illness, Crisis and Loss | volume = 18 | issue = 1 }}</ref> There are many scientific approaches and various interpretations of the concept. Additionally, the advent of life-sustaining therapy and the numerous criteria for defining death from both a medical and legal standpoint have made it difficult to create a single unifying definition.<ref>{{Cite book |last1=Veatch |first1=Robert M. |title=Defining Death: The Case for Choice |last2=Ross |first2=Lainie F. |date= 2016 |publisher=[[Georgetown University Press]] |isbn=978-1-62616-356-0 }}</ref>

==== Defining life to define death ====
One of the challenges in defining death is in distinguishing it from life. As a point in time, death seems to refer to the moment when life ends. Determining when death has occurred is difficult, as cessation of life functions is often not simultaneous across organ systems.<ref>{{cite magazine |title=Crossing Over: How Science Is Redefining Life and Death |url=https://www.nationalgeographic.com/magazine/2016/04/dying-death-brain-dead-body-consciousness-science/ |author=Henig, Robin Marantz |author-link=Robin Marantz Henig |magazine=[[National Geographic (magazine)|National Geographic]] |date=April 2016 |access-date=23 October 2017 |archive-date=1 November 2017 |archive-url=https://web.archive.org/web/20171101071129/https://www.nationalgeographic.com/magazine/2016/04/dying-death-brain-dead-body-consciousness-science/ }}</ref> Such determination, therefore, requires drawing precise conceptual boundaries between life and death. This is difficult due to there being little consensus on how to define life.
[[File:StillLifeWithASkull.jpg|thumb|left|alt=Symbols of death in a painting: it shows a flower, a skull and an hourglass|A flower, a skull, and an hourglass stand for life, death, and time in this 17th-century painting by [[Philippe de Champaigne]].]]

It is possible to define life in terms of consciousness. When consciousness ceases, an organism can be said to have died. One of the flaws in this approach is that there are many organisms that are alive but probably not conscious.<ref>{{Cite web |last=Animal Ethics |date=2023 |title=What beings are not conscious |url=https://www.animal-ethics.org/beings-conscious/#:~:text=Non%2Dsentient%20animals%20would%20then,and%20even%20engage%20in%20locomotion. |access-date=February 14, 2023 |website=Animal Ethics |archive-date=8 November 2014 |archive-url=https://web.archive.org/web/20141108091811/https://www.animal-ethics.org/beings-conscious/#:~:text=Non%2Dsentient%20animals%20would%20then,and%20even%20engage%20in%20locomotion. |url-status=live }}</ref> Another problem is in defining consciousness, which has many different definitions given by modern scientists, psychologists and philosophers.<ref>{{Cite journal |last=Antony |first=Micheal V. |date=2001 |title=Is 'consciousness' ambiguous? |url=https://philpapers.org/rec/ANTICA#:~:text=It%20is%20widely%20assumed%20that,consciousness%2C%20to%20name%20a%20few. |journal=Journal of Consciousness Studies |volume=8 |issue=2 |pages=19–44 |via=PhilPapers |access-date=14 February 2023 |archive-date=6 March 2023 |archive-url=https://web.archive.org/web/20230306150630/https://philpapers.org/rec/ANTICA#:~:text=It%20is%20widely%20assumed%20that,consciousness%2C%20to%20name%20a%20few. |url-status=live }}</ref> Additionally, many religious traditions, including [[Abrahamic religions|Abrahamic]] and [[Dharmic religions|Dharmic]] traditions, hold that death does not (or may not) entail the end of consciousness. In certain cultures, death is more of a process than a single event. It implies a slow shift from one spiritual state to another.<ref>{{cite book|year=1991 |last1=Metcalf |first1=Peter |last2=Huntington |first2=Richard |title=Celebrations of Death: The Anthropology of Mortuary Ritual |publisher=Cambridge Press |place=New York}}{{page needed|date=January 2014}}</ref>

Other definitions for death focus on the character of cessation of organismic functioning and human death, which refers to irreversible loss of personhood. More specifically, death occurs when a living entity experiences irreversible cessation of all functioning.<ref name="DeGrazia-2017" /> As it pertains to human life, death is an irreversible process where someone loses their existence as a person.<ref name="DeGrazia-2017">{{Citation|last=DeGrazia|first=David|title=The Definition of Death|date=2017|url=https://plato.stanford.edu/archives/spr2017/entries/death-definition/|encyclopedia=The Stanford Encyclopedia of Philosophy|editor-last=Zalta|editor-first=Edward N.|edition=Spring 2017|publisher=Metaphysics Research Lab, Stanford University|access-date=2019-02-19|archive-date=18 March 2019|archive-url=https://web.archive.org/web/20190318071254/https://plato.stanford.edu/archives/spr2017/entries/death-definition/|url-status=live}}</ref>

==== Definition of death by heartbeat and breath ====
Historically, attempts to define the exact moment of a human's death have been subjective or imprecise. Death was defined as the cessation of [[heart]]beat (cardiac arrest) and [[breath]]ing,<ref name="US President's Commission -1981">{{Cite book |last=United States. President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research |url=https://books.google.com/books?id=fd3sFRTejuIC |title=Defining Death: A Report on the Medical, Legal and Ethical Issues in the Determination of Death · Part 34 |publisher=The Commission |year=1981 |page=63 |access-date=19 March 2023 |archive-date=17 August 2023 |archive-url=https://web.archive.org/web/20230817193515/https://books.google.com/books?id=fd3sFRTejuIC |url-status=live }}</ref> but the development of [[cardiopulmonary resuscitation|CPR]] and prompt [[defibrillation]] have rendered that definition inadequate because breathing and heartbeat can sometimes be restarted.<ref name="US Department of the Army-1999">{{Cite book |last=United States Department of the Army |url=https://books.google.com/books?id=YLdfpIvnkZQC&q=CPR |title=Leadership Education and Training (LET 1) |publisher=United States Department of the Army |year=1999 |page=188 |access-date=19 March 2023 |archive-date=17 August 2023 |archive-url=https://web.archive.org/web/20230817193517/https://books.google.com/books?id=YLdfpIvnkZQC&q=CPR |url-status=live }}</ref> This type of death where circulatory and respiratory arrest happens is known as the circulatory definition of death (CDD). Proponents of the CDD believe this definition is reasonable because a person with permanent loss of circulatory and respiratory function should be considered dead.<ref name="Bernat-2018">{{cite journal|last=Bernat|first=James L.|date=2018|title=Conceptual Issues in DCDD Donor Death Determination|journal=Hastings Center Report|volume=48|issue=S4|pages=S26–S28|doi=10.1002/hast.948|pmid=30584853|issn=1552-146X|doi-access=free}}</ref> Critics of this definition state that while cessation of these functions may be permanent, it does not mean the situation is irreversible because if CPR is applied fast enough, the person could be revived.<ref name="Bernat-2018"/> Thus, the arguments for and against the CDD boil down to defining the actual words "permanent" and "irreversible," which further complicates the challenge of defining death. Furthermore, events [[causality|causally]] linked to death in the past no longer kill in all circumstances; without a functioning heart or lungs, life can sometimes be sustained with a combination of [[life support]] devices, [[organ transplants]], and [[artificial pacemaker]]s.

==== Brain death ====
Today, where a definition of the moment of death is required, doctors and coroners usually turn to "brain death" or "biological death" to define a person as being dead;<ref>{{Cite book |last=Belkin |first=Gary Stuart |title=Death Before Dying: History, Medicine, and Brain Death. |publisher=[[Oxford University Press]] |year=2014 |isbn=978-0-19-989817-6 |page=220}}</ref> people are considered dead when the electrical activity in their brain ceases.<ref>{{Cite web |last=New York State Department of Health |date=2011 |title=Guidelines for Determining Brain Death |url=https://www.health.ny.gov/professionals/hospital_administrator/letters/2011/brain_death_guidelines.htm |access-date=February 15, 2023 |website=New York State |archive-date=24 January 2012 |archive-url=https://web.archive.org/web/20120124021515/https://www.health.ny.gov/professionals/hospital_administrator/letters/2011/brain_death_guidelines.htm |url-status=live }}</ref> It is presumed that an end of electrical activity indicates the end of [[consciousness]].<ref>{{Cite web |last=National Health Service of the UK |date=September 8, 2022 |title=Overview: Brain death |url=https://www.nhs.uk/conditions/brain-death/#:~:text=Brain%20death%20(also%20known%20as,is%20legally%20confirmed%20as%20dead. |access-date=February 15, 2023 |website=National Health Service |archive-date=12 November 2008 |archive-url=https://web.archive.org/web/20081112175311/https://www.nhs.uk/conditions/brain-death/#:~:text=Brain%20death%20(also%20known%20as,is%20legally%20confirmed%20as%20dead. |url-status=live }}</ref> Suspension of consciousness must be permanent and not transient, as occurs during certain [[non-rapid eye movement sleep|sleep]] stages, and especially a coma.<ref>{{Cite web |last=Nitkin |first=Karen |date=September 11, 2017 |title=The Challenges of Defining and Diagnosing Brain Death |url=https://www.hopkinsmedicine.org/news/articles/the-challenges-of-defining-and-diagnosing-brain-death#:~:text=Brain%20death%3A%20Irreversible%20cessation%20of,severe%20illness%20or%20brain%20injury. |access-date=February 15, 2023 |website=Johns Hopkins Medicine |archive-date=10 October 2019 |archive-url=https://web.archive.org/web/20191010230354/https://www.hopkinsmedicine.org/news/articles/the-challenges-of-defining-and-diagnosing-brain-death#:~:text=Brain%20death%3A%20Irreversible%20cessation%20of,severe%20illness%20or%20brain%20injury. |url-status=live }}</ref> In the case of sleep, Electroencephalogram ([[electroencephalography|EEGs]]) are used to tell the difference.<ref>{{Cite book |last1=Chernecky |first1=Cynthia C. |title=Laboratory Tests and Diagnostic Procedures |last2=Berger |first2=Barbara J. |year=2013 |publisher=Saunders |isbn=978-1-4557-0694-5 |edition=6th }}</ref>

The category of "brain death" is seen as problematic by some scholars. For instance, Dr. Franklin Miller, a senior faculty member at the Department of Bioethics, National Institutes of Health, notes: "By the late 1990s... the equation of brain death with death of the human being was increasingly challenged by scholars, based on evidence regarding the array of biological functioning displayed by patients correctly diagnosed as having this condition who were maintained on mechanical ventilation for substantial periods of time. These patients maintained the ability to sustain circulation and respiration, control temperature, excrete wastes, heal wounds, fight infections and, most dramatically, to gestate fetuses (in the case of pregnant "brain-dead" women)."<ref name=Miller>{{cite journal|last=Miller|first=F.G.|title=Death and organ donation: back to the future|journal=Journal of Medical Ethics|date=October 2009 |volume=35 |issue=10 |pages=616–620 |doi=10.1136/jme.2009.030627 |pmid=19793942|doi-access=free}}</ref>

[[File:French - Pendant with a Monk and Death - Walters 71461.jpg|thumb|alt=Ivory pendant of a Monk's face. The left half of the pendant appears skeletal, while the right half appears living|French – 16th-/17th-century ivory pendant, Monk and Death, recalling mortality and the certainty of death ([[Walters Art Museum]])]]

While "brain death" is viewed as problematic by some scholars, there are proponents of it{{Who|date=November 2023}} that believe this definition of death is the most reasonable for distinguishing life from death. The reasoning behind the support for this definition is that brain death has a set of criteria that is reliable and reproducible. Also, the brain is crucial in determining our identity or who we are as human beings. The distinction should be made that "brain death" cannot be equated with one in a vegetative state or coma, in that the former situation describes a state that is beyond recovery.<ref name="Magnus-2014">{{cite journal |last1=Magnus |first1=David C. |last2=Wilfond |first2=Benjamin S. |last3=Caplan |first3=Arthur L. |date=2014-03-06 |title=Accepting Brain Death |journal=New England Journal of Medicine |volume=370 |issue=10 |pages=891–894 |doi=10.1056/NEJMp1400930 |issn=0028-4793 |pmid=24499177}}</ref>

EEGs can detect spurious electrical impulses, while certain drugs, [[hypoglycemia]], [[hypoxia (medical)|hypoxia]], or [[hypothermia]] can suppress or even stop brain activity temporarily;<ref>{{Cite journal |last1=Nicol |first1=A. U. |last2=Morton |first2=A. J. |date=June 11, 2020 |title=Characteristic patterns of EEG oscillations in sheep (Ovis aries) induced by ketamine may explain the psychotropic effects seen in humans. |journal=Scientific Reports |volume=10 |issue=1 |page=9440 |doi=10.1038/s41598-020-66023-8 |pmid=32528071 |pmc=7289807 |bibcode=2020NatSR..10.9440N }}</ref> because of this, hospitals have protocols for determining brain death involving EEGs at widely separated intervals under defined conditions.<ref>{{Cite web |last=New York Department of Health |date=December 5, 2011 |title=Guidelines for Determining Brain Death |url=https://www.health.ny.gov/professionals/hospital_administrator/letters/2011/brain_death_guidelines.htm#:~:text=Electroencephalography%20(EEG)%3A%20Brain%20death,criteria%20listed%20in%20Appendix%202. |access-date=February 15, 2023 |website=New York State |archive-date=24 January 2012 |archive-url=https://web.archive.org/web/20120124021515/https://www.health.ny.gov/professionals/hospital_administrator/letters/2011/brain_death_guidelines.htm#:~:text=Electroencephalography%20(EEG)%3A%20Brain%20death,criteria%20listed%20in%20Appendix%202. |url-status=live }}</ref>

==== Neocortical brain death ====
People maintaining that only the [[neo-cortex]] of the brain is necessary for consciousness sometimes argue that only electrical activity should be considered when defining death. Eventually, the criterion for death may be the permanent and irreversible loss of [[cognition|cognitive]] function, as evidenced by the death of the [[cerebral cortex]]. All hope of recovering human thought and [[personality psychology|personality]] is then gone, given current and foreseeable medical technology.<ref name="Zaner-2011">{{Cite book |last=Zaner |first=Richard M. |title=Death: Beyond Whole-Brain Criteria |date=2011 |publisher=[[Springer Publishing Company|Springer]] |isbn=978-94-010-7720-0 |edition=1st |pages=77, 125}}</ref> Even by whole-brain criteria, the determination of brain death can be complicated.

==== Total brain death ====
At present, in most places, the more conservative definition of death&nbsp;(– irreversible cessation of electrical activity in the whole brain, as opposed to just in the neo-cortex&nbsp;– )has been adopted. One example is the [[Uniform Determination Of Death Act]] in the United States.<ref>{{Cite book |last1=National Conference of Commissioners on Uniform State Laws |url=https://lchc.ucsd.edu/cogn_150/Readings/death_act.pdf |title=Uniform Determination of Death Act |last2=American Bar Association |last3=American Medical Association |year=1981 |access-date=15 February 2023 |archive-date=26 March 2023 |archive-url=https://web.archive.org/web/20230326130414/https://lchc.ucsd.edu/cogn_150/Readings/death_act.pdf |url-status=live }}</ref> In the past, the adoption of this whole-brain definition was a conclusion of the President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research in 1980.<ref>{{Cite journal|last1=Lewis|first1=Ariane|last2=Cahn-Fuller|first2=Katherine|last3=Caplan|first3=Arthur|date=March 2017|title=Shouldn't Dead Be Dead?: The Search for a Uniform Definition of Death|journal=The Journal of Law, Medicine & Ethics|volume=45|issue=1|pages=112–128|doi=10.1177/1073110517703105|pmid=28661278|s2cid=4388540|issn=1073-1105}}</ref> They concluded that this approach to defining death sufficed in reaching a uniform definition nationwide. A multitude of reasons was presented to support this definition, including uniformity of standards in law for establishing death, consumption of a family's fiscal resources for artificial life support, and legal establishment for equating brain death with death to proceed with organ donation.<ref>{{Cite journal|last=Sarbey|first=Ben|date=2016-12-01|title=Definitions of death: brain death and what matters in a person|journal=Journal of Law and the Biosciences|volume=3|issue=3|pages=743–752|doi=10.1093/jlb/lsw054|pmid=28852554|pmc=5570697}}</ref>

==== Problems in medical practice ====
Aside from the issue of support of or dispute against brain death, there is another inherent problem in this categorical definition: the variability of its application in medical practice. In 1995, the American Academy of Neurology (AAN) established the criteria that became the medical standard for diagnosing neurologic death. At that time, three clinical features had to be satisfied to determine "irreversible cessation" of the total brain, including coma with clear etiology, cessation of breathing, and lack of brainstem reflexes.<ref name="Bernat-2013">{{Cite journal|last=Bernat|first=James L.|date=March 2013|title=Controversies in defining and determining death in critical care|journal=Nature Reviews Neurology|volume=9|issue=3|pages=164–173|doi=10.1038/nrneurol.2013.12|pmid=23419370|s2cid=12296259|issn=1759-4766}}</ref> These criteria were updated again, most recently in 2010, but substantial discrepancies remain across hospitals and medical specialties.<ref name="Bernat-2013" />

==== Donations ====
The problem of defining death is especially imperative as it pertains to the [[dead donor rule]], which could be understood as one of the following interpretations of the rule: there must be an official declaration of death in a person before starting organ procurement, or that organ procurement cannot result in the death of the donor.<ref name="Bernat-2018" /> A great deal of controversy has surrounded the definition of death and the dead donor rule. Advocates of the rule believe that the rule is legitimate in protecting organ donors while also countering any moral or legal objection to organ procurement. Critics, on the other hand, believe that the rule does not uphold the best interests of the donors and that the rule does not effectively promote organ donation.<ref name="Bernat-2018" />

===Signs===
{{main|Stages of death}}

Signs of death or strong indications that a [[endotherm|warm-blooded animal]] is no longer alive are:<ref>{{Cite web |last=Australian Department of Health and Aged Care |date=June 2021 |title=The physical process of dying |url=https://www.healthdirect.gov.au/the-physical-process-of-dying |access-date=February 15, 2023 |website=Health Direct |archive-date=1 March 2020 |archive-url=https://web.archive.org/web/20200301223347/https://www.healthdirect.gov.au/the-physical-process-of-dying |url-status=live }}</ref>
* [[Respiratory arrest]] (no [[breathing]])
* [[Cardiac arrest]] (no [[heart rate|pulse]])
* [[Brain death]] (no neuronal activity)

The stages that follow after death are:<ref name="Dolinak-2005">{{Cite book |last1=Dolinak |first1=David |title=Forensic Pathology: Principles and Practice |last2=Matshes |first2=Evan |last3=Lew |first3=Emma O. |publisher=[[Elsevier Academic Press]] |isbn=978-0-08-047066-5 |date= 2005 |page=526}}</ref>
* {{lang|la|[[Pallor mortis]]}}, paleness which happens in 15–120 minutes after death
* {{lang|la|[[Algor mortis]]}}, the reduction in body temperature following death. This is generally a steady decline until matching ambient temperature
* {{lang|la|[[Rigor mortis]]}}, the limbs of the corpse become stiff (Latin ''rigor'') and difficult to move or manipulate
* {{lang|la|[[Livor mortis]]}}, a settling of the blood in the lower (dependent) portion of the body
* [[Putrefaction]], the beginning signs of decomposition
* [[Decomposition]], the reduction into simpler forms of matter, accompanied by a strong, unpleasant odor.
* [[Skeletonization]], the end of decomposition, where all soft tissues have decomposed, leaving only the skeleton.
* [[Fossil]]ization, the natural preservation of the skeletal remains formed over a very long period
[[File:Postmortem interval changes (stages of death).png|thumb|center|upright=3|Timeline of postmortem changes (stages of death)]]

===Legal===
{{See also|Legal death}}

The death of a person has legal consequences that may vary between jurisdictions. Most countries follow the whole-brain death criteria, where all functions of the brain must have completely ceased. However, in other jurisdictions, some follow the brainstem version of brain death.<ref name="Bernat-2013" /> Afterward, a [[death certificate]] is issued in most jurisdictions, either by a doctor or by an administrative office, upon presentation of a doctor's declaration of death.<ref>{{Cite book |last=World Health Organization |title=Medical Certification of Cause of Death: Instructions for Physicians on Use of International Form of Medical Certificate of Cause of Death |publisher=[[World Health Organization]] |year=1979 |isbn=978-92-4-156062-7}}</ref>

===Misdiagnosis===
{{See also|Premature burial}}
[[File:Wiertz burial.jpg|thumb|upright=1.2|''The Premature Burial'', [[Antoine Wiertz]]'s painting of a man buried alive, 1854]]

There are many anecdotal references to people being declared dead by physicians and then "coming back to life," sometimes days later in their coffin or when [[embalming]] procedures are about to begin. From the mid-18th century onwards, there was an upsurge in the public's fear of being mistakenly buried alive<ref>{{Harvnb|Bondeson|2001|p=77}}</ref> and much debate about the uncertainty of the signs of death. Various suggestions were made to test for signs of life before burial, ranging from pouring vinegar and pepper into the corpse's mouth to applying red hot pokers to the feet or into the [[rectum]].<ref>{{Harvnb|Bondeson|2001|pp=56,&nbsp;71.}}</ref> Writing in 1895, the physician J.C. Ouseley claimed that as many as 2,700 people were buried prematurely each year in England and Wales, although some estimates peg the figure to be closer to 800.<ref>{{Harvnb|Bondeson|2001|p=239}}</ref>

In cases of [[electric shock]], [[cardiopulmonary resuscitation]] (CPR) for an hour or longer can allow stunned [[nerve]]s to recover, allowing an apparently dead person to survive. People found unconscious under icy water may survive if their faces are kept continuously cold until they arrive at an [[emergency room]].<ref name=Limmer>{{cite book |title=Brady Emergency Care AHA |publisher=Prentice Hall |isbn=978-0-13-159390-9 |author1=Limmer, Dan |author2=O'Keefe, Michael F. |author3=Bergeron, J. David |author4=Grant, Harvey |author5=Murray, Bob |author6=Dickinson, Ed |edition=10th Updated |date=21 December 2006 |url-access=registration |url=https://archive.org/details/emergencycare0000unse }}</ref><!--original citation:Limmer, D. et al. (2006). Emergency care (AHA update, Ed. 10e). [[Prentice Hall]].--><!--guessed it was this:https://www.amazon.com/Brady-Emergency-Care-Updated-Edition/dp/0131593900/ --> This "diving response," in which [[metabolism|metabolic activity]] and oxygen requirements are minimal, is something humans share with [[cetacea]]ns called the [[mammalian diving reflex]].<ref name=Limmer />

As medical technologies advance, ideas about when death occurs may have to be reevaluated in light of the ability to restore a person to vitality after longer periods of apparent death (as happened when CPR and defibrillation showed that cessation of heartbeat is inadequate as a decisive indicator of death). The lack of electrical brain activity may not be enough to consider someone scientifically dead. Therefore, the concept of information-theoretic death has been suggested as a better means of defining when true death occurs, though the concept has few practical applications outside the field of [[cryonics]].<ref name="InfoDeath">{{cite web |last=Merkle |first=Ralph |title=Information-Theoretic Death |url=http://www.merkle.com/definitions/infodeath.html |url-status=live |archive-url=https://web.archive.org/web/20160809190714/http://www.merkle.com/definitions/infodeath.html |archive-date=9 August 2016 |access-date=4 June 2016 |website=merkle.com |quote="A person is dead according to the information-theoretic criterion if the structures that encode memory and personality have been so disrupted that it is no longer possible in principle to recover them. If inference of the state of memory and personality are feasible in principle, and therefore restoration to an appropriate functional state is likewise feasible in principle, then the person is not dead."}}</ref>