Allegory of death: skeleton holding banderolle "Vigilate quia nescitis diem ...", anon., possibly Dutch or German. Made c.1600
Death – particularly the death of
humans – has commonly been considered a
sad or unpleasant occasion, due to the
affection for the being that has died and the termination of social and familial
bonds with the deceased. Other concerns include
fear of death,
necrophobia,
anxiety,
sorrow,
grief,
emotional pain,
depression,
sympathy,
compassion,
solitude, or
saudade. Many cultures and religions have the idea of an
afterlife, and also hold the idea of
reward or
judgement and
punishment for past sin.
Etymology
The word death comes from
Old English dēaþ, which in turn comes from Proto-Germanic *
dauþuz (reconstructed by etymological analysis). This comes from the Proto-Indo-European stem *
dheu- meaning the "Process, act, condition of dying".
Associated terms
The concept and symptoms of death, and varying degrees of delicacy used in discussion in public forums, have generated numerous scientific, legal, and socially acceptable terms or euphemisms for death. When a person has died, it is also said they have
passed away,
passed on,
expired, or are
gone, among numerous other socially accepted, religiously specific, slang, and irreverent terms. Bereft of life, the dead person is then a
corpse,
cadaver, a
body, a
set of remains, and when all flesh has rotted away, a
skeleton. The terms
carrion and
carcass can also be used, though these more often connote the remains of non-human animals. As a polite reference to a dead person, it has become common practice to use the
participle form of "decease", as in
the deceased; another noun form is
decedent. The ashes left after a
cremation are sometimes referred to by the
neologism cremains, a
portmanteau of "cremation" and "remains".
Senescence
Senescence refers to a scenario when a living being is able to survive all calamities, but eventually dies due to causes relating to old age. Animal and plant cells normally reproduce and function during the whole period of natural existence, but the aging process derives from deterioration of cellular activity and ruination of regular functioning. Aptitude of cells for gradual deterioration and mortality means that cells are naturally sentenced to stable and long-term loss of living capacities, even despite continuing metabolic reactions and viability. In the United Kingdom, for example, nine out of ten of all the deaths that occur on a daily basis relates to senescence, while around the world it accounts for two-thirds of 150,000 deaths that take place daily (Hayflick & Moody, 2003).
Almost all
animals who survive external hazards to their biological functioning eventually die from
biological aging, known in life sciences as "senescence". Some organisms experience
negligible senescence, even exhibiting
biological immortality. These include the jellyfish
Turritopsis dohrnii, the
hydra, and the
planarian. Unnatural causes of death include
suicide and
homicide. From all causes, roughly 150,000 people die around the world each day. Of these, two thirds die directly or indirectly due to senescence, but in industrialized countries—such as the United States, the United Kingdom, and Germany—the rate approaches 90%, i.e., nearly nine out of ten of all deaths are related to senescence.
Physiological death is now seen as a process, more than an event: conditions once considered indicative of death are now reversible. Where in the process a dividing line is drawn between life and death depends on factors beyond the presence or absence of
vital signs. In general,
clinical death is neither necessary nor sufficient for a determination of
legal death. A patient with working
heart and
lungs determined to be
brain dead can be pronounced legally dead without clinical death occurring. As
scientific knowledge and
medicineadvance, formulating a precise medical definition of death becomes more difficult.
Diagnosis
Number of deaths per million persons in 2012
1054-4,598
4,599-5,516
5,517-6,289
6,290-6,835
6,836-7,916
7,917-8,728
8,729-9,404
9,405-10,433
10,434-12,233
12,234-17,141
Signs
- Respiratory arrest (no breathing)
- Cardiac arrest (no pulse)
- Pallor mortis, paleness which happens in the 15–120 minutes after death
- Livor mortis, a settling of the blood in the lower (dependent) portion of the body
- Algor mortis, the reduction in body temperature following death. This is generally a steady decline until matching ambient temperature
- Rigor mortis, the limbs of the corpse become stiff (Latin rigor) and difficult to move or manipulate
- Decomposition, the reduction into simpler forms of matter, accompanied by a strong, unpleasant odor.
problems of definition
French – 16th-/17th-century ivory pendant, Monk and Death, recalling mortality and the certainty of death (
Walters Art Museum)
The concept of death is a key to human understanding of the phenomenon. There are many scientific approaches to the concept. For example, brain death, as practiced in medical science, defines death as a point in time at which brain activity ceases.
One of the challenges in defining death is in distinguishing it from
life. As a point in time, death would seem to refer to the moment at which life ends. Determining when death has occurred requires drawing precise conceptual boundaries between life and death. This is difficult, due to there being little consensus on how to define life. This general problem applies to the particular challenge of defining death in the context of medicine.
It is possible to define life in terms of consciousness. When consciousness ceases, a living organism can be said to have died. One of the flaws in this approach is that there are many organisms which are alive but probably not conscious (for example, single-celled organisms). Another problem is in defining consciousness, which has many different definitions given by modern scientists, psychologists and philosophers. Additionally, many religious traditions, including
Abrahamic and
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.
Other definitions for death focus on the character of cessation of something. In this context "death" describes merely the state where something has ceased, for example, life. Thus, the definition of "life" simultaneously defines death.
Historically, attempts to define the exact moment of a human's death have been subjective, or imprecise. Death was once defined as the cessation of
heartbeat (
cardiac arrest) and of
breathing, but the development of
CPR and prompt defibrillation have rendered that definition inadequate because breathing and heartbeat can sometimes be restarted. Events which were
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 pacemakers.
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; people are considered dead when the electrical activity in their brain ceases. It is presumed that an end of electrical activity indicates the end of
consciousness. Suspension of consciousness must be permanent, and not transient, as occurs during certain
sleep stages, and especially a
coma. In the case of sleep,
EEGs can easily tell the difference.
The category of "brain death" is seen as problematic by some scholars. For instance, Dr. Franklin Miller, 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)."
Those 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 it is possible that the criterion for death will be the permanent and irreversible loss of
cognitive function, as evidenced by the death of the
cerebral cortex. All hope of recovering human thought and
personality is then gone given current and foreseeable medical technology. At present, in most places the more conservative definition of death – irreversible cessation of electrical activity in the whole brain, as opposed to just in the neo-cortex – has been adopted (for example the
Uniform Determination Of Death Act in the United States). In 2005, the
Terri Schiavo case brought the question of brain death and artificial sustenance to the front of
American politics.
Even by whole-brain criteria, the determination of brain death can be complicated. EEGs can detect spurious electrical impulses, while certain
drugs,
hypoglycemia,
hypoxia, or
hypothermia can suppress or even stop brain activity on a temporary basis. Because of this, hospitals have protocols for determining brain death involving EEGs at widely separated intervals under defined conditions.
Legal
The death of a person has legal consequences that may vary between different jurisdictions. 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.
Misdiagnosed
There are many anecdotal references to people being declared dead by physicians and then "coming back to life", sometimes days later in their own 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, 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. 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 others estimated the figure to be closer to 800.
In cases of
electric shock,
cardiopulmonary resuscitation (CPR) for an hour or longer can allow stunned
nerves 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. This "diving response", in which
metabolic activity and oxygen requirements are minimal, is something humans share with
cetaceans called the
mammalian diving reflex.As medical technologies advance, ideas about when death occurs may have to be re-evaluated 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 of the field of
cryonics.
There have been some scientific attempts to bring dead organisms back to life, but with limited success. In
science fiction scenarios where such technology is readily available, real death is distinguished from reversible death.
Cause
The leading cause of human death in
developing countries is
infectious disease. The leading causes in
developed countries are
atherosclerosis (
heart disease and
stroke),
cancer, and other diseases related to
obesity and
aging. By an extremely wide margin, the largest unifying cause of death in the developed world is biological aging, leading to various complications known as
aging-associated diseases. These conditions cause loss of
homeostasis, leading to
cardiac arrest, causing loss of
oxygen and nutrient supply, causing irreversible deterioration of the
brain and other
tissues. Of the roughly 150,000 people who die each day across the globe, about two thirds die of age-related causes. In industrialized nations, the proportion is much higher, approaching 90%. With improved medical capability, dying has become
a condition to be managed. Home deaths, once commonplace, are now rare in the developed world.
Americans smoking in 1910.
Tobacco smoking caused an estimated 100 million deaths in the 20th century.
According to
Jean Ziegler (
United Nations Special Reporter on the Right to Food, 2000—Mar 2008), mortality due to
malnutrition accounted for 58% of the total mortality rate in 2006. Ziegler says worldwide approximately 62M people died from all causes and of those deaths more than 36M died of hunger or diseases due to deficiencies in
micronutrients.
Tobacco smoking killed 100 million people worldwide in the 20th century and could kill 1 billion people around the world in the 21st century, a
World Health Organization report warned.
Many leading developed world causes of death can be postponed by
diet and
physical activity, but the accelerating incidence of disease with age still imposes limits on human
longevity. The
evolutionary cause of aging is, at best, only just beginning to be understood. It has been suggested that direct intervention in the aging process may now be the most effective intervention against major causes of death.
Selye proposed a unified non-specific approach to many causes of death. He demonstrated that
stress decreases adaptability of an organism and proposed to describe the adaptability as a special resource,
adaptation energy. The animal dies when this resource is exhausted.Selye assumed that the adaptability is a finite supply, presented at birth. Later on, Goldstone proposed the concept of a production or income of adaptation energy which may be stored (up to a limit), as a capital reserve of adaptation. In recent works, adaptation energy is considered as an internal coordinate on the "dominant path" in the model of adaptation. It is demonstrated that oscillations of well-being appear when the reserve of adaptability is almost exhausted.
In 2012,
suicide overtook car crashes for leading causes of human injury deaths in the U.S., followed by poisoning, falls and murder. Causes of death are different in different parts of the world. In high-income and middle income countries nearly half up to more than two thirds of all people live beyond the age of 70 and predominantly die of chronic diseases. In low-income countries, where less than one in five of all people reach the age of 70, and more than a third of all deaths are among children under 15, people predominantly die of infectious diseases.
Autopsy
Autopsies are either performed for legal or medical purposes. A forensic autopsy is carried out when the cause of death may be a criminal matter, while a clinical or academic autopsy is performed to find the medical cause of death and is used in cases of unknown or uncertain death, or for research purposes. Autopsies can be further classified into cases where external examination suffices, and those where the body is dissected and an internal examination is conducted. Permission from
next of kin may be required for internal autopsy in some cases. Once an internal autopsy is complete the body is generally reconstituted by sewing it back together. Autopsy is important in a medical environment and may shed light on mistakes and help improve practices.
A "necropsy" is an older term for a postmortem examination, unregulated, and not always a medical procedure. In modern times the term is more often used in the postmortem examination of the corpses of animals.
Cryonics
Cryopreservation of people or large animals is not reversible with current technology. The stated rationale for cryonics is that people who are considered dead by current legal or medical definitions may not necessarily be dead according to the more stringent information-theoretic definition of death. It is proposed that cryopreserved people might someday be recovered by using highly advanced technology.
Some scientific literature supports the feasibility of cryonics. Many other scientists regard cryonics with skepticism. By 2015, more than 300 people have undergone
cryopreservation procedures since cryonics was first proposed in 1962.
Life extension
A United States poll found that religious people and irreligious people, as well as men and women and people of different economic classes have similar rates of support for life extension, while Africans and Hispanics have higher rates of support than white people. 38 percent of the polled said they would desire to have their aging process cured.
Researchers of life extension are a subclass of biogerontologists known as "biomedical
gerontologists". They try to understand the nature of aging and they develop treatments to reverse aging processes or to at least slow them down, for the improvement of health and the maintenance of youthful vigor at every stage of life. Those who take advantage of life extension findings and seek to apply them upon themselves are called "life extensionists" or "longevists". The primary life extension strategy currently is to apply available anti-aging methods in the hope of living long enough to benefit from a complete cure to aging once it is developed.
Reperfusion
"One of medicine's new frontiers: treating the dead", recognizes that cells that have been without oxygen for more than five minutes die, not from lack of oxygen, but rather when their oxygen supply is resumed. Therefore, practitioners of this approach, e.g., at the Resuscitation Science institute at the
University of Pennsylvania, "aim to reduce oxygen uptake, slow metabolism and adjust the blood chemistry for gradual and safe
reperfusion."
Location
Before about 1930, most people in Western countries died in their own homes, surrounded by family, and comforted by clergy, neighbors, and doctors making
house calls. By the mid-20th century, half of all Americans died in a hospital. By the start of the 21st century, only about 20 to 25% of people in developed countries died outside a medical institution. The shift away from dying at home, towards dying in a professionalized medical environment, has been termed the "Invisible Death". The "Invisible Death" process was extremely slow and infinitesimal. It took many years to shift to this new location where dying was commonly taking place outside of the home.
Society and culture
Commemoration ceremonies after death may include various
mourning,
funeral practices and ceremonies of honouring the deceased. The physical remains of a person, commonly known as a
corpse or
body, are usually
interred whole or
cremated, though among the world's cultures there are a variety of other methods of
mortuary disposal. In the English language, blessings directed towards a dead person include
rest in peace, or its
initialism RIP.
Death is the center of many traditions and organizations; customs relating to death are a feature of every culture around the world. Much of this revolves around the care of the dead, as well as the
afterlife and the disposal of bodies upon the onset of death. The
disposal of human corpses does, in general, begin with the
last offices before significant time has passed, and ritualistic ceremonies often occur, most commonly interment or
cremation. This is not a unified practice; in
Tibet, for instance, the body is given a
sky burial and left on a mountain top. Proper preparation for death and techniques and ceremonies for producing the ability to transfer one's spiritual attainments into another body (
reincarnation) are subjects of detailed study in Tibet.
Mummification or
embalming is also prevalent in some cultures, to retard the rate of
decay.
Gravestones in
Kyoto, Japan
Capital punishment is also a culturally divisive aspect of death. In most jurisdictions where capital punishment is carried out today, the death penalty is reserved for premeditated
murder,
espionage,
treason, or as part of
military justice. In some countries, sexual crimes, such as
adultery and
sodomy, carry the death penalty, as do religious crimes such as
apostasy, the formal renunciation of one's religion. In many
retentionist countries,
drug trafficking is also a capital offense. In China,
human trafficking and serious cases of
corruption are also punished by the death penalty. In militaries around the world
courts-martial have imposed death sentences for offenses such as
cowardice,
desertion,
insubordination, and
mutiny.
Suicide in general, and particularly
euthanasia, are also points of cultural debate. Both acts are understood very differently in different cultures. In
Japan, for example, ending a life with honor by
seppuku was considered a desirable death, whereas according to traditional Christian and Islamic cultures, suicide is viewed as a sin.
Death is personified in many cultures, with such symbolic representations as the
Grim Reaper,
Azrael, the
Hindu God
Yama and
Father Time.
In
Brazil, a human death is counted officially when it is registered by existing family members at a cartório, a government-authorized registry. Before being able to file for an official death, the deceased must have been registered for an official birth at the cartório. Though a Public Registry Law guarantees all Brazilian citizens the right to register deaths, regardless of their financial means, of their family members (often children), the Brazilian government has not taken away the burden, the hidden costs and fees, of filing for a death. For many impoverished families, the indirect costs and burden of filing for a death lead to a more appealing, unofficial, local, cultural burial, which in turn raises the debate about inaccurate
mortality rates.
Talking about death and witnessing it is a difficult issue with most cultures. Western societies may like to treat the dead with the utmost material respect, with an official embalmer and associated rites. Eastern societies (like India) may be more open to accepting it as a fait accompli, with a funeral procession of the dead body ending in an open air burning-to-ashes of the same.
Consciousness
Much interest and debate surround the question of what happens to one's consciousness as one's body dies. The belief in the permanent loss of consciousness after death is often called
eternal oblivion. Belief that consciousness is preserved after physical death is described by the term
afterlife.
In biology
Microorganisms also play a vital role, raising the temperature of the decomposing matter as they break it down into yet simpler molecules. Not all materials need to be decomposed fully.
Coal, a
fossil fuel formed over vast tracts of time in
swamp ecosystems, is one example.
Natural selection
Contemporary
evolutionary theory sees death as an important part of the process of
natural selection. It is considered that organisms less
adapted to their environment are more likely to die having produced fewer offspring, thereby reducing their contribution to the
gene pool. Their genes are thus eventually bred out of a population, leading at worst to
extinction and, more positively, making the process possible, referred to as
speciation. Frequency of
reproduction plays an equally important role in determining species survival: an organism that dies young but leaves numerous offspring displays, according to
Darwinian criteria, much greater
fitness than a long-lived organism leaving only one.
Extinction
A
dodo, the bird that became a
byword in the English language for the extinction of a species
Extinction is the cessation of existence of a species or group of
taxa, reducing
biodiversity. The moment of extinction is generally considered to be the death of the last individual of that species (although the
capacity to breed and recover may have been lost before this point). Because a species' potential
range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as
Lazarus taxa, where species presumed extinct abruptly "reappear" (typically in the
fossil record) after a period of apparent absence. New species arise through the process of
speciation, an aspect of
evolution. New varieties of organisms arise and thrive when they are able to find and exploit an
ecological niche – and species become extinct when they are no longer able to survive in changing conditions or against superior competition
Evolution of aging and mortality
Inquiry into the evolution of aging aims to explain why so many living things and the vast majority of animals weaken and die with age (exceptions include
Hydra and the already cited jellyfish
Turritopsis dohrnii, which research shows to be
biologically immortal). The evolutionary origin of
senescence remains one of the fundamental puzzles of biology.
Gerontology specializes in the science of human aging processes.
Organisms showing only
asexual reproduction (e.g.
bacteria, some
protists, like the
euglenoids and many
amoebozoans) and
unicellular organisms with
sexual reproduction (
colonial or not, like the
volvocine algae
Pandorina and
Chlamydomonas) are "immortal" at some extent, dying only due to external hazards, like being eaten or meeting with a fatal accident. In
multicellular organisms (and also in
multinucleate ciliates), with a
Weismannist development, that is, with a division of labor between mortal
somatic (body) cells and "immortal"
germ (reproductive) cells, death becomes an essential part of life, at least for the somatic line.
The
Volvox algae are among the simplest organisms to exhibit that division of labor between two completely different cell types, and as a consequence include death of somatic line as a regular, genetically regulated part of its
life history.
It is not only humans and mammals that give birth. Some reptiles, amphibians, fish and invertebrates carry their developing young inside them. Some of these are ovoviviparous, with the eggs being hatched inside the mother's body, and others are viviparous, with the embryodeveloping inside her body, as in mammals.
Most smaller mammals have multiple births, producing litters of young which may number twelve or more. In these animals, each fetus is surrounded by its own amniotic sac and has a separate placenta. This separates from the wall of the uterus during labor and the fetus works its way towards the birth canal..
Enormous changes take place in the newborn's circulation to enable breathing in air. In the uterus, the unborn baby is dependent on circulation of blood through the placenta for sustenance including gaseous exchange and the unborn baby's blood bypasses the lungs by flowing though the foramen ovale, which is a hole in the septum dividing the right atrium and left atrium. After birth the umbilical cord is clamped and cut, the baby starts to breathe air, and blood from the right ventricle starts to flow to the lungs for gaseous exchange and oxygenated blood returns to the left atrium, which is pumped into the left ventricle, and then pumped into the main arterial system. As result of these changes, the blood pressure in the left atrium exceeds the pressure in the right atrium, and this pressure difference forces the foramen ovale to close separating the left and right sides of the heart. The umbilical vein, umbilical arteries, ductus venosus and ductus arteriosus are not needed for life in air and in time these vessels become ligaments (embryonic remnants).
Birth is termed whelping in dogs. Among dogs, as whelping approaches, contractions become more frequent. Labour in the bitch can be divided into 3 stages. The first stage is when the cervix dilates, this causes discomfort and restlessness in the bitch. Common signs of this stage are panting, fasting, and/or vomiting. This may last up to 12hrs. Stage two is the passage of the offspring. The amniotic sac looking like a glistening grey balloon, with a puppy inside, is propelled through the vulva. After further contractions, the sac is expelled and the bitch breaks the membranes releasing clear fluid and exposing the puppy. The mother chews at the umbilical cord and licks the puppy vigorously, which stimulates it to breathe. If the puppy has not taken its first breath within about six minutes, it is likely to die. Further puppies follow in a similar way one by one usually with less straining than the first usually at 15-60min intervals. If a pup has not been passed in 2 hrs a veterinarian should be contacted. Stage three is the passing of the placentas. This often occurs in conjunction with stage two with the passing of each offspring The mother will then usually eat the afterbirth. This is an adaption to keep the den clean and prevent detection of predators.
