Death is the
irreversible cessation of all
biological functions that sustain an
organism
In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...
. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and
brain death is sometimes used as a legal definition of death. The remains of a former organism normally begin to
decompose
Decomposition or rot is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is ...
shortly after death. Death is an inevitable process that eventually occurs in
almost all organisms.
Death is generally applied to whole organisms; the similar process seen in individual components of an organism, such as cells or tissues, is
necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...
. Something that is not considered an organism, such as a
virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's 1 ...
, can be physically destroyed but is not said to die. As of the early 21st century, over 150,000 humans die each day, with
ageing
Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In ...
being by far the most common
cause of death
In law, medicine, and statistics, cause of death is an official determination of conditions resulting in a human's death, which may be recorded on a death certificate. A cause of death is determined by a medical examiner. The cause of death is ...
.
Many cultures and religions have the idea of an
afterlife
The afterlife (also referred to as life after death) is a purported existence in which the essential part of an individual's identity or their stream of consciousness continues to live after the death of their physical body. The surviving ess ...
, and also may hold the idea of
judgement
Judgement (or US spelling judgment) is also known as ''adjudication'', which means the evaluation of evidence to make a decision. Judgement is also the ability to make considered decisions. The term has at least five distinct uses. Aristotle s ...
of good and bad deeds in one's life (
heaven
Heaven or the heavens, is a common religious cosmological or transcendent supernatural place where beings such as deities, angels, souls, saints, or venerated ancestors are said to originate, be enthroned, or reside. According to the belie ...
,
hell
In religion and folklore, hell is a location in the afterlife in which evil souls are subjected to punitive suffering, most often through torture, as eternal punishment after death. Religions with a linear divine history often depict hell ...
,
karma
Karma (; sa, कर्म}, ; pi, kamma, italic=yes) in Sanskrit means an action, work, or deed, and its effect or consequences. In Indian religions, the term more specifically refers to a principle of cause and effect, often descriptivel ...
).
Diagnosis
Problems of definition
The concept of death is a key to human understanding of the phenomenon.
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.
One of the challenges in defining death is in distinguishing it from
life
Life is a quality that distinguishes matter that has biological processes, such as signaling and self-sustaining processes, from that which does not, and is defined by the capacity for growth, reaction to stimuli, metabolism, energ ...
. As a point in time, death would seem to refer to the moment at which life ends. Determining when death has occurred is difficult, as cessation of life functions is often not simultaneous across organ systems. 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.
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 (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
The Abrahamic religions are a group of religions centered around worship of the God of Abraham. Abraham, a Hebrew patriarch, is extensively mentioned throughout Abrahamic religious scriptures such as the Bible and the Quran.
Jewish tradition ...
and
Dharmic
Dharma (; sa, धर्म, dharma, ; pi, dhamma, italic=yes) is a key concept with multiple meanings in Indian religions, such as Hinduism, Buddhism, Jainism, Sikhism and others. Although there is no direct single-word translation for '' ...
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 organismic functioning and a human death which refers to irreversible loss of personhood. More specifically, death occurs when a living entity experiences irreversible cessation of all functioning.
As it pertains to human life, death is an irreversible process where someone loses their existence as a person.
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
heart
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...
beat (
cardiac arrest
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possib ...
) and of
breath
Breathing (or ventilation) is the process of moving air into and from the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen.
All aerobic creatures need oxygen for cellular ...
ing, but the development of
CPR
Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation in an effort to manually preserve intact brain function until further measures are taken to restore sponta ...
and prompt
defibrillation
Defibrillation is a treatment for life-threatening cardiac arrhythmias, specifically ventricular fibrillation (V-Fib) and non-perfusing ventricular tachycardia (V-Tach). A defibrillator delivers a dose of electric current (often called a ''cou ...
have rendered that definition inadequate because breathing and heartbeat can sometimes be restarted. This type of death where circulatory and respiratory arrest happens is known as the circulatory definition of death (DCDD). Proponents of the DCDD believe that this definition is reasonable because a person with permanent loss of circulatory and respiratory function should be considered dead.
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 was applied, the person could be revived.
Thus, the arguments for and against the DCDD boil down to a matter of defining the actual words "permanent" and "irreversible," which further complicates the challenge of defining death. Furthermore, 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
Life support comprises the treatments and techniques performed in an emergency in order to support life after the failure of one or more vital organs. Healthcare providers and emergency medical technicians are generally certified to perform basic ...
devices,
organ transplants
Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transpo ...
and
artificial pacemaker
An artificial cardiac pacemaker (or artificial pacemaker, so as not to be confused with the natural cardiac pacemaker) or pacemaker is a medical device that generates electrical impulses delivered by electrodes to the chambers of the heart eit ...
s.
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
Consciousness, at its simplest, is sentience and awareness of internal and external existence. However, the lack of definitions has led to millennia of analyses, explanations and debates by philosophers, theologians, linguisticians, and scien ...
. Suspension of consciousness must be permanent, and not transient, as occurs during certain
sleep
Sleep is a sedentary state of mind and body. It is characterized by altered consciousness, relatively inhibited sensory activity, reduced muscle activity and reduced interactions with surroundings. It is distinguished from wakefulness by a de ...
stages, and especially a
coma
A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to respond normally to painful stimuli, light, or sound, lacks a normal wake-sleep cycle and does not initiate voluntary actions. Coma patients exhi ...
. 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)."
While "brain death" is viewed as problematic by some scholars, there are certainly proponents of it 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 who is in a vegetative state or coma, in that the former situation describes a state that is beyond recovery.
Those people maintaining that only the
neo-cortex
The neocortex, also called the neopallium, isocortex, or the six-layered cortex, is a set of layers of the mammalian cerebral cortex involved in higher-order brain functions such as sensory perception, cognition, generation of motor commands, sp ...
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
Cognition refers to "the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought, ...
function, as evidenced by the death of the
cerebral cortex
The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of ...
. All hope of recovering human thought and
personality
Personality is the characteristic sets of behaviors, cognitions, and emotional patterns that are formed from biological and environmental factors, and which change over time. While there is no generally agreed-upon definition of personality, mos ...
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
The Uniform Determination of Death Act (UDDA) is a model state law that was approved for the United States in 1981 by the National Conference of Commissioners on Uniform State Laws, in cooperation with the American Medical Association, the America ...
in the United States). In 2005, the
Terri Schiavo case
The Terri Schiavo case was a series of court and legislative actions in the United States from 1998 to 2005, regarding the care of Theresa Marie Schiavo (née Schindler) (; December 3, 1963 – March 31, 2005), a woman in an irreversible ...
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
A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhalat ...
,
hypoglycemia
Hypoglycemia, also called low blood sugar, is a fall in blood sugar to levels below normal, typically below 70 mg/dL (3.9 mmol/L). Whipple's triad is used to properly identify hypoglycemic episodes. It is defined as blood glucose bel ...
,
hypoxia, or
hypothermia
Hypothermia is defined as a body core temperature below in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe ...
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.
In the past, 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. They concluded that this approach to defining death sufficed in reaching a uniform definition nationwide. A multitude of reasons were 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 in order to proceed with organ donation.
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 a set of criteria that became the medical standard for diagnosing neurologic death. At that time, three clinical features had to be satisfied in order to determine "irreversible cessation" of the total brain including: coma with clear etiology, cessation of breathing, and lack of brainstem reflexes.
This set of criteria was then updated again most recently in 2010, but substantial discrepancies still remain across hospitals and medical specialties.
The problem of defining death is especially imperative as it pertains to the
dead donor rule Prior to the introduction of brain death into law in the mid to late 1970s, all organ transplants from cadaveric donors came from non-heart-beating donors (NHBDs).
Donors after brain death (DBD) (beating heart cadavers), however, led to better resu ...
, 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 death of the donor.
A great deal of controversy has surrounded the definition of death and the dead donor rule. Advocates of the rule believe the rule is legitimate in protecting organ donors while also countering against 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.
Signs
Signs of death or strong indications that a
warm-blooded animal is no longer alive are:
*
Respiratory arrest
Respiratory arrest is a sickness caused by apnea (cessation of breathing) or respiratory dysfunction severe enough it will not sustain the body (such as agonal breathing). Prolonged apnea refers to a patient who has stopped breathing for a long p ...
(no
breathing
Breathing (or ventilation) is the process of moving air into and from the lungs to facilitate gas exchange with the internal environment, mostly to flush out carbon dioxide and bring in oxygen.
All aerobic creatures need oxygen for cellular ...
)
*
Cardiac arrest
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possib ...
(no
pulse
In medicine, a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the n ...
)
*
Brain death (no neuronal activity)
The stages that follow after death are:
* , paleness which happens in 15–120 minutes after death
* , the reduction in body temperature following death. This is generally a steady decline until matching ambient temperature
* , the limbs of the corpse become stiff (Latin ''rigor'') and difficult to move or manipulate
* , a settling of the blood in the lower (dependent) portion of the body
*
Putrefaction
Putrefaction is the fifth stage of death, following pallor mortis, algor mortis, rigor mortis, and livor mortis. This process references the breaking down of a body of an animal, such as a human, post-mortem. In broad terms, it can be viewed ...
, the beginning signs of decomposition
*
Decomposition
Decomposition or rot is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is e ...
, the reduction into simpler forms of matter, accompanied by a strong, unpleasant odor.
*
Skeletonization
Skeletonization is the state of a dead organism after undergoing decomposition.The Australian Museum. (2018). Decomposition-Body Changes. Retrieved from: https://australianmuseum.net.au/about/history/exhibitions/death-the-last-taboo/decomposit ...
, the end of decomposition, where all soft tissues have decomposed, leaving only the skeleton.
*
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
ization, the natural preservation of the skeletal remains formed over a very long period
Legal
The death of a person has legal consequences that may vary between different jurisdictions.
A
death certificate
A death certificate is either a legal document issued by a medical practitioner which states when a person died, or a document issued by a government civil registration office, that declares the date, location and cause of a person's death, as ...
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
Embalming is the art and science of preserving human remains by treating them (in its modern form with chemicals) to forestall decomposition. This is usually done to make the deceased suitable for public or private viewing as part of the funeral ...
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
Burial, also known as interment or inhumation, is a method of final disposition whereby a dead body is placed into the ground, sometimes with objects. This is usually accomplished by excavating a pit or trench, placing the deceased and objec ...
, ranging from pouring vinegar and pepper into the corpse's mouth to applying red hot pokers to the feet or into the
rectum
The rectum is the final straight portion of the large intestine in humans and some other mammals, and the Gastrointestinal tract, gut in others. The adult human rectum is about long, and begins at the rectosigmoid junction (the end of the s ...
. 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
Electrical injury is a physiological reaction caused by electric current passing through the body. The injury depends on the density of the current, tissue resistance and duration of contact. Very small currents may be imperceptible or produce ...
,
cardiopulmonary resuscitation
Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation in an effort to manually preserve intact brain function until further measures are taken to restore spont ...
(CPR) for an hour or longer can allow stunned
nerve
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system.
A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the e ...
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
An emergency department (ED), also known as an accident and emergency department (A&E), emergency room (ER), emergency ward (EW) or casualty department, is a medical treatment facility specializing in emergency medicine, the acute care of pati ...
.
This "diving response", in which
metabolic activity
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
and oxygen requirements are minimal, is something humans share with
cetacea
Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...
ns called the
mammalian diving reflex
The diving reflex, also known as the diving response and mammalian diving reflex, is a set of physiological responses to immersion that overrides the basic homeostatic reflexes, and is found in all air-breathing vertebrates studied to date. It o ...
.
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 the field of
cryonics
Cryonics (from el, κρύος ''kryos'' meaning 'cold') is the low-temperature freezing (usually at ) and storage of human remains, with the speculative hope that resurrection may be possible in the future. Cryonics is regarded with skepticis ...
.
There have been some scientific attempts to bring dead organisms back to life, but with limited success.
Causes
The leading cause of human death in
developing countries
A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreem ...
is
infectious disease
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...
. The leading causes in
developed countries
A developed country (or industrialized country, high-income country, more economically developed country (MEDC), advanced country) is a sovereign state that has a high quality of life, developed economy and advanced technological infrastruct ...
are
atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheroma, atheromatous plaque. At onset there are usu ...
(
heart disease
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, hea ...
and
stroke),
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
, and other diseases related to
obesity
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's we ...
and
aging
Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In ...
. 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
An aging-associated disease (commonly termed age-related disease, ARD) is a disease that is most often seen with increasing frequency with increasing senescence. They are essentially complications of senescence, distinguished from the aging pr ...
. These conditions cause loss of
homeostasis
In biology, homeostasis (British English, British also homoeostasis) Help:IPA/English, (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physics, physical, and chemistry, chemical conditions maintained by organism, living systems. Thi ...
, leading to
cardiac arrest
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possib ...
, causing loss of
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
and nutrient supply, causing irreversible deterioration of the
brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...
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
Dying is the final stage of life which will eventually lead to death. Diagnosing dying is a complex process of clinical decision-making, and most practice checklists facilitating this diagnosis are based on cancer diagnoses.
Signs of dying ...
has become
a condition to be managed. Home deaths, once commonplace, are now rare in the developed world.
In
developing nations
A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreeme ...
, inferior sanitary conditions and lack of access to modern
medical technology
Health technology is defined by the World Health Organization as the "application of organized knowledge and skills in the form of devices, medicines, vaccines, procedures, and systems developed to solve a health problem and improve quality of liv ...
makes death from
infectious diseases
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...
more common than in
developed countries
A developed country (or industrialized country, high-income country, more economically developed country (MEDC), advanced country) is a sovereign state that has a high quality of life, developed economy and advanced technological infrastruct ...
. One such disease is
tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...
, a bacterial disease which killed 1.8M people in 2015.
Malaria
Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...
causes about 400–900M cases of fever and 1–3M deaths annually.
AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual m ...
death toll in Africa may reach 90–100M by 2025.
According to
Jean Ziegler
Jean Ziegler (; born Hans Ziegler, 19 April 1934) is a Swiss former professor of sociology at the University of Geneva and the Sorbonne, Paris, and former vice-president of the Advisory Committee to the United Nations Human Rights Council. He ...
(
United Nations
The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and international security, security, develop friendly relations among nations, achieve international cooperation, and be ...
Special Reporter on the Right to Food, 2000 – Mar 2008), mortality due to
malnutrition
Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is "a deficiency, excess, or imbalance of energy, protein and other nutrients" which adversely affects the body's tissues a ...
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
Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...
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
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of h ...
report warned.
Many leading developed world causes of death can be postponed by
diet
Diet may refer to:
Food
* Diet (nutrition), the sum of the food consumed by an organism or group
* Dieting, the deliberate selection of food to control body weight or nutrient intake
** Diet food, foods that aid in creating a diet for weight loss ...
and
physical activity
Physical activity is defined as any voluntary bodily movement produced by skeletal muscles that requires energy expenditure.Global Recommendations on Physical Activity for Health, 2009. World Health Organization. Geneva, Switzerland. Accessed 13/ ...
, but the accelerating incidence of disease with age still imposes limits on human
longevity
The word " longevity" is sometimes used as a synonym for "life expectancy" in demography. However, the term ''longevity'' is sometimes meant to refer only to especially long-lived members of a population, whereas ''life expectancy'' is always d ...
. 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
Stress may refer to:
Science and medicine
* Stress (biology), an organism's response to a stressor such as an environmental condition
* Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...
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, H. (1938). Experimental evidence supporting the conception of "adaptation energy", Am. J. Physiol. 123 (1938), 758–765.] 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
Suicide is the act of intentionally causing one's own death. Mental disorders (including depression, bipolar disorder, schizophrenia, personality disorders, anxiety disorders), physical disorders (such as chronic fatigue syndrome), and s ...
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
An
autopsy
An autopsy (post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death or to evaluate any di ...
, also known as a ''postmortem examination'' or an ''obduction'', is a
medical procedure
A medical procedure is a course of action intended to achieve a result in the delivery of healthcare.
A medical procedure with the intention of determining, measuring, or diagnosing a patient condition or parameter is also called a medical test. ...
that consists of a thorough
examination of a human
corpse
A cadaver or corpse is a dead human body that is used by medical students, physicians and other scientists to study anatomy, identify disease sites, determine causes of death, and provide tissue to repair a defect in a living human being. Stu ...
to determine the cause and manner of a person's death and to evaluate any
disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
or
injury
An injury is any physiological damage to living tissue caused by immediate physical stress. An injury can occur intentionally or unintentionally and may be caused by blunt trauma, penetrating trauma, burning, toxic exposure, asphyxiation, o ...
that may be present. It is usually performed by a specialized
medical doctor
A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...
called a
pathologist
Pathology is the study of the causal, causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when us ...
.
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, which is not always a medical procedure, was a term previously used to describe an unregulated postmortem examination. In modern times, this term is more commonly associated with the corpses of animals.
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.
Almost all
animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
s who survive external hazards to their biological functioning eventually die from
biological aging
Senescence () or biological aging is the gradual deterioration of functional characteristics in living organisms. The word ''senescence'' can refer to either cellular senescence or to senescence of the whole organism. Organismal senescence inv ...
, known in life sciences as "senescence". Some organisms experience
negligible senescence
Negligible senescence is a term coined by biogerontologist Caleb Finch to denote organisms that do not exhibit evidence of biological aging (senescence), such as measurable reductions in their reproductive capability, measurable functional decline ...
, even exhibiting
biological immortality. These include the jellyfish ''
Turritopsis dohrnii
''Turritopsis dohrnii'', also known as the immortal jellyfish, is a species of small, biologically immortal jellyfish found worldwide in temperate to tropic waters. It is one of the few known cases of animals capable of reverting completely to ...
'', the
hydra, and the
planarian
A planarian is one of the many flatworms of the traditional class Turbellaria. It usually describes free-living flatworms of the order Tricladida (triclads), although this common name is also used for a wide number of free-living platyhelmint ...
. Unnatural causes of death include
suicide
Suicide is the act of intentionally causing one's own death. Mental disorders (including depression, bipolar disorder, schizophrenia, personality disorders, anxiety disorders), physical disorders (such as chronic fatigue syndrome), and s ...
and
predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
. 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
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...
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
Vital signs (also known as vitals) are a group of the four to six most crucial medical signs that indicate the status of the body's vital (life-sustaining) functions. These measurements are taken to help assess the general physical health of a ...
. In general,
clinical death is neither necessary nor sufficient for a determination of
legal death
Legal death is the recognition under the law of a particular jurisdiction that a person is no longer alive. In most cases, a doctor's declaration of death (variously called) or the identification of a corpse is a legal requirement for such recognit ...
. A patient with working
heart
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...
and
lungs
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side ...
determined to be
brain dead
Brain death is the permanent, irreversible, and complete loss of brain function which may include cessation of involuntary activity necessary to sustain life. It differs from persistent vegetative state, in which the person is alive and some aut ...
can be pronounced legally dead without clinical death occurring.
Cryonics
Cryonics (from Greek κρύος 'kryos-' meaning 'icy cold') is the
low-temperature preservation of animals and humans who cannot be sustained by contemporary medicine, with the hope that healing and
resuscitation may be possible in the future.
Cryopreservation
Cryo-preservation or cryo-conservation is a process where organisms, organelles, cells, tissues, extracellular matrix, organs, or any other biological constructs susceptible to damage caused by unregulated chemical kinetics are preserved by co ...
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.
Some scientific literature is claimed to support the feasibility of cryonics.
Medical science and cryobiologists generally regards cryonics with skepticism.
Life extension
Life extension refers to an increase in
maximum
In mathematical analysis, the maxima and minima (the respective plurals of maximum and minimum) of a function, known collectively as extrema (the plural of extremum), are the largest and smallest value of the function, either within a given r ...
or
average lifespan, especially in humans, by slowing down or reversing the
processes of aging through
anti-aging
The anti-aging movement is a social movement devoted to eliminating or reversing aging, or reducing the effects of it. A substantial portion of the attention of the movement is on the possibilities for life extension, but there is also interest in ...
measures. Despite the fact that aging is by far the most common cause of death worldwide, it is socially mostly ignored as such and seen as "necessary" and "inevitable" anyway, which is why little money is spent on research into anti-aging therapies, a phenomenon known as the
pro-aging trance
Pro-aging trance, also known as pro-aging edifice, is a term coined by British author and biomedical gerontologist Aubrey de Grey to describe the broadly positive and fatalistic attitude toward aging in society.
Overview
According to de Grey, ...
.
Average lifespan is determined by vulnerability to
accident
An accident is an unintended, normally unwanted event that was not directly caused by humans. The term ''accident'' implies that nobody should be blamed, but the event may have been caused by unrecognized or unaddressed risks. Most researche ...
s and age or lifestyle-related afflictions such as
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
, or
cardiovascular disease
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, h ...
. Extension of average lifespan can be achieved by good
diet
Diet may refer to:
Food
* Diet (nutrition), the sum of the food consumed by an organism or group
* Dieting, the deliberate selection of food to control body weight or nutrient intake
** Diet food, foods that aid in creating a diet for weight loss ...
,
exercise
Exercise is a body activity that enhances or maintains physical fitness and overall health and wellness.
It is performed for various reasons, to aid growth and improve strength, develop muscles and the cardiovascular system, hone athletic ...
and avoidance of hazards such as
smoking
Smoking is a practice in which a substance is burned and the resulting smoke is typically breathed in to be tasted and absorbed into the bloodstream. Most commonly, the substance used is the dried leaves of the tobacco plant, which have bee ...
. Maximum lifespan is also determined by the rate of
aging
Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In ...
for a species inherent in its
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
s. Currently, the only widely recognized method of extending maximum lifespan is
calorie restriction
Calorie restriction (caloric restriction or energy restriction) is a dietary regimen that reduces intake of energy from caloric foods & beverages without incurring malnutrition. "Reduce" can be defined relative to the subject's previous intake b ...
. Theoretically, extension of maximum lifespan can be achieved by reducing the rate of aging damage, by
periodic replacement of damaged tissues, or by
molecular repair or
rejuvenation
Rejuvenation is a medical discipline focused on the practical reversal of the aging process.
Rejuvenation is distinct from life extension. Life extension strategies often study the causes of aging and try to oppose those causes in order to slow ...
of deteriorated cells and tissues.
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
gerontologist
Gerontology ( ) is the study of the social, cultural, psychological, cognitive, and biological aspects of aging. The word was coined by Ilya Ilyich Mechnikov in 1903, from the Greek , ''geron'', "old man" and , ''-logia'', "study of". Th ...
s". 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.
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 call
A house call is medical consultation performed by a doctor or other healthcare professionals visiting the home of a patient
A patient is any recipient of health care services that are performed by healthcare professionals. The patient is ...
s.
By the mid-20th century, half of all Americans died in a hospital.
By the start of the 21st century, only about 20–25% of people in developed countries died outside of a medical institution.
The shift away from dying at home towards dying in a professional medical environment has been termed the "Invisible Death".
This shift occurred gradually over the years, until most deaths now occur outside the home.
Psychology
Death studies is a field within
psychology
Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries betwe ...
.
Many people are afraid of
dying
Dying is the final stage of life which will eventually lead to death. Diagnosing dying is a complex process of clinical decision-making, and most practice checklists facilitating this diagnosis are based on cancer diagnoses.
Signs of dying ...
. Discussing, thinking about, or planning for their own deaths causes them discomfort. This fear may cause them to put off financial planning, preparing a
will and testament
A will or testament is a legal document that expresses a person's (testator) wishes as to how their property ( estate) is to be distributed after their death and as to which person ( executor) is to manage the property until its final distributi ...
, or requesting help from a
hospice
Hospice care is a type of health care that focuses on the palliation of a terminally ill patient's pain and symptoms and attending to their emotional and spiritual needs at the end of life. Hospice care prioritizes comfort and quality of life by ...
organization.
Different people have different responses to the idea of their own deaths. Philosopher
Galen Strawson
Galen John Strawson (born 1952) is a British analytic philosopher and literary critic who works primarily on philosophy of mind, metaphysics (including free will, panpsychism, the mind-body problem, and the self), John Locke, David Hume, ...
writes that the death that many people wish for is an instant, painless, unexperienced annihilation.
In this unlikely scenario, the person dies without realizing it and without being able to fear it. One moment the person is walking, eating, or sleeping, and the next moment, the person is dead. Strawson reasons that this type of death would not take anything away from the person, as he believes that a person cannot have a legitimate claim to ownership in the future.
Society and culture
In society, the nature of death and humanity's
awareness of its own mortality has for millennia been a concern of the world's
religious traditions
Religion is usually defined as a social-cultural system of designated behaviors and practices, morals, beliefs, worldviews, texts, sanctified places, prophecies, ethics, or organizations, that generally relates humanity to supernatural, tra ...
and of
philosophical inquiry. This includes belief in
resurrection
Resurrection or anastasis is the concept of coming back to life after death. In a number of religions, a dying-and-rising god is a deity which dies and is resurrected. Reincarnation is a similar process hypothesized by other religions, which ...
or an
afterlife
The afterlife (also referred to as life after death) is a purported existence in which the essential part of an individual's identity or their stream of consciousness continues to live after the death of their physical body. The surviving ess ...
(associated with
Abrahamic religions
The Abrahamic religions are a group of religions centered around worship of the God of Abraham. Abraham, a Hebrew patriarch, is extensively mentioned throughout Abrahamic religious scriptures such as the Bible and the Quran.
Jewish tradition ...
),
reincarnation
Reincarnation, also known as rebirth or transmigration, is the philosophical or religious concept that the non-physical essence of a living being begins a new life in a different physical form or body after biological death. Resurrection is a ...
or rebirth (associated with
Dharmic religions
Indian religions, sometimes also termed Dharmic religions or Indic religions, are the religions that originated in the Indian subcontinent. These religions, which include Hinduism, Jainism, Buddhism, and Sikhism,Adams, C. J."Classification of ...
), or that consciousness permanently ceases to exist, known as
eternal oblivion
Eternal oblivion (also referred to as non-existence or nothingness) is the philosophical or religious concept of one's consciousness forever ceasing upon death. Pamela Health and Jon Klimo write that this concept is mostly associated with religio ...
(associated with
Secular humanism).
Commemoration ceremonies after death may include various
mourning
Mourning is the expression of an experience that is the consequence of an event in life involving loss, causing grief, occurring as a result of someone's death, specifically someone who was loved although loss from death is not exclusively ...
,
funeral
A funeral is a ceremony connected with the final disposition of a corpse, such as a burial or cremation, with the attendant observances. Funerary customs comprise the complex of beliefs and practices used by a culture to remember and respect th ...
practices and ceremonies of honouring the deceased. The physical remains of a person, commonly known as a ''corpse'' or ''body'', are usually burial, interred whole or cremated, though among the world's cultures there are a variety of other methods of Disposal of human corpses, mortuary disposal. In the English language, blessings directed towards a dead person include ''rest in peace'' (originally the Latin ''requiescat in pace''), 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
The afterlife (also referred to as life after death) is a purported existence in which the essential part of an individual's identity or their stream of consciousness continues to live after the death of their physical body. The surviving ess ...
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
Reincarnation, also known as rebirth or transmigration, is the philosophical or religious concept that the non-physical essence of a living being begins a new life in a different physical form or body after biological death. Resurrection is a ...
) are subjects of detailed study in Tibet. Mummification or
embalming
Embalming is the art and science of preserving human remains by treating them (in its modern form with chemicals) to forestall decomposition. This is usually done to make the deceased suitable for public or private viewing as part of the funeral ...
is also prevalent in some cultures, to retard the rate of Decomposition, decay.
Legal aspects of death are also part of many cultures, particularly the settlement of the deceased estate (law), estate and the issues of inheritance and in some countries, inheritance taxation.
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 Use of capital punishment by nation, retentionist countries, drug trafficking is also a capital offense. In China, Trafficking in human beings, human trafficking and serious cases of political corruption, 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.
Death in warfare and in suicide attack also have cultural links, and the ideas of ''dulce et decorum est pro patria mori'', mutiny punishable by death, grieving relatives of dead soldiers and death notification are embedded in many cultures. Recently in the western world, with the increase in terrorism following the September 11 attacks, but also further back in time with suicide bombings, kamikaze missions in World War II and suicide missions in a host of other conflicts in history, death for a cause by way of suicide attack, and martyrdom have had significant cultural impacts.
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 (personification), Death is personified in many cultures, with such symbolic representations as the Death (personification), 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
Eternal oblivion (also referred to as non-existence or nothingness) is the philosophical or religious concept of one's consciousness forever ceasing upon death. Pamela Health and Jon Klimo write that this concept is mostly associated with religio ...
''. Belief that the Stream of consciousness (psychology), stream of consciousness is preserved after physical death is described by the term ''
afterlife
The afterlife (also referred to as life after death) is a purported existence in which the essential part of an individual's identity or their stream of consciousness continues to live after the death of their physical body. The surviving ess ...
''. Neither are likely to ever be confirmed without the ponderer having to actually die.
In biology
After death, the remains of a former organism become part of the biogeochemical cycle, during which animals may be necrophagy, consumed by a predator or a scavenger. Organic material may then be further decomposed by detritivores, organisms which recycle detritus, returning it to the environment for reuse in the food chain, where these chemicals may eventually end up being consumed and assimilated into the cells of an organism. Examples of detritivores include earthworms, woodlice and dung beetles.
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 fully decomposed. Coal, a fossil fuel formed over vast tracts of time in swamp ecosystems, is one example.
Natural selection
Contemporary history of evolutionary thought, evolutionary theory sees death as an important part of the process of natural selection. It is considered that organisms less adaptation, 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 biological reproduction, reproduction plays an equally important role in determining species survival: an organism that dies young but leaves numerous offspring displays, according to Charles Darwin, Darwinian criteria, much greater Darwinian fitness, fitness than a long-lived organism leaving only one.
Extinction
Extinction is the cessation of existence of a species or group of Taxon, taxa, reducing biodiversity. The moment of extinction is generally considered to be the death of the last individual of that species (although the population bottleneck, capacity to breed and recover may have been lost before this point). Because a species' potential range (biology), range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxon, 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 (genus), Hydra'' and the jellyfish ''
Turritopsis dohrnii
''Turritopsis dohrnii'', also known as the immortal jellyfish, is a species of small, biologically immortal jellyfish found worldwide in temperate to tropic waters. It is one of the few known cases of animals capable of reverting completely to ...
'', which research shows to be biological immortality, 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 (Colony (biology), colonial or not, like the Volvocales, 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 Weismann barrier, Weismannist development, that is, with a division of labor between mortal somatic cells, somatic (body) cells and "immortal" germ cell, 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 Biological life cycle, life history.
Religious views
Buddhism
In Buddhist doctrine and practice, death plays an important role. Awareness of death was what motivated Gautama Buddha, Prince Siddhartha to strive to find the amrta#Theravada Buddhism, "deathless" and finally to attain enlightenment (Buddhism), enlightenment. In Buddhist doctrine, death functions as a reminder of the value of Human beings in Buddhism, having been born as a human being. Being reborn as a human being is considered the only state in which one can attain enlightenment. Therefore, death helps remind oneself that one should not take life for granted. The belief in rebirth among Buddhists does not necessarily remove existential angst, death anxiety, since all existence in the samsara (Buddhism), cycle of rebirth is considered filled with dukkha, suffering, and being reborn many times does not necessarily mean that one progresses.
Death is part of several key Buddhist tenets, such as the Four Noble Truths and Pratītyasamutpāda, dependent origination.
Christianity
While there are different sects of Christianity with different branches of belief; the overarching ideology on death grows from the knowledge of afterlife. Meaning after death the individual will undergo a separation from mortality to immortality; their soul leaves the body entering a realm of spirits. Following this separation of body and spirit (i.e. death)
resurrection
Resurrection or anastasis is the concept of coming back to life after death. In a number of religions, a dying-and-rising god is a deity which dies and is resurrected. Reincarnation is a similar process hypothesized by other religions, which ...
will occur. Representing the same transformation Jesus, Jesus Christ embodied after his body was placed in the tomb for three days. Like Jesus, Him, each person's body will be resurrected reuniting the spirit and body in a perfect form. This process allows the individuals soul to withstand death and transform into life after death.
Hinduism
In Hindu texts, death is described as the individual eternal spiritual ''Jiva, jiva-atma'' (soul or conscious self) exiting the current temporary material body. The soul exits this body when the body can no longer sustain the conscious self (life), which may be due to mental or physical reasons, or more accurately, the inability to act on one's ''Kama#In Hinduism, kama'' (material desires). During conception, the soul enters a compatible new body based on the remaining merits and demerits of one's ''Karma#In Hinduism, karma'' (good/bad material activities based on ''Dharma#Hinduism, dharma'') and the state of one's mind (impressions or last thoughts) at the time of death.
Usually the process of Reincarnation#Hinduism, reincarnation (soul's transmigration) makes one forget all memories of one's previous life. Because nothing really dies and the temporary material body is always changing, both in this life and the next, death means forgetfulness of one's previous experiences (previous material identity).
Material existence is described as being full of miseries arising from birth, disease, old age, death, mind, weather, etc. To conquer ''Saṃsāra, samsara'' (the cycle of death and rebirth) and become eligible for one of the different types of ''moksha'' (liberation), one has to first conquer ''Kama#In Hinduism, kama'' (material desires) and become Enlightenment (spiritual), self-realized. The human form of life is most suitable for this spiritual journey, especially with the help of ''sadhu'' (self-realized saintly persons), ''sastra'' (revealed spiritual scriptures), and ''guru'' (self-realized spiritual masters), given all three are in agreement.
Islam
The Islamic view is that death is the separation of the soul from the body as well as the beginning of the afterlife. The afterlife or ''akhirah'' is one of the six main beliefs in Islam. Rather than seeing death as the end of life, Muslims consider death as a continuation of life in another form. In Islam, the life on earth right now is a short, temporary life and a testing period for every soul. The true life begins with the Day of Judgement, when all people will be divided into two groups. The righteous believers will be welcomed to ''Jannah, janna'' (heaven) and the disbelievers and evildoers will be punished in ''jahannam'' (hellfire).
Muslims believe death to be wholly natural and predetermined by God. Only God knows the exact time of a person’s death. Quran, The Quran emphasizes that death is inevitable, no matter how much people try to escape death, it will reach everyone. Life on earth is the one and only chance for people to prepare themselves for the life to come and choose to either believe or not believe in God, and death is the end of that learning opportunity.
Judaism
There are a Jewish eschatology#The world to come, variety of beliefs about the afterlife within Judaism, but none of them contradict the preference of life over death. This is partially because death puts a cessation to the possibility of fulfilling any Mitzvah, commandments.
Language
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
Dying is the final stage of life which will eventually lead to death. Diagnosing dying is a complex process of clinical decision-making, and most practice checklists facilitating this diagnosis are based on cancer diagnoses.
Signs of dying ...
".
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. When a person has died, it is also said they have "passed away", "passed on", "expired", or "gone", among other socially accepted, religiously specific, slang, and irreverent terms.
As a formal 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 "wikt:decedent, decedent".
Bereft of life, the dead person is a "corpse", "cadaver", "body", "set of remains" or, when all flesh is gone, a "skeleton". The terms "carrion" and "carcass" are also used, usually for dead non-human animals. The ashes left after a cremation are lately called "cremains".
See also
* Casualty (person)
* Day of Judgment
* Day of the Dead
* wikt: deathbed, Deathbed
* Death drive
* Death row
* Death trajectory
* Dying
* Dying declaration
* End-of-life care
* Eschatology
* Faked death
* Karōshi
* Last rites
* List of deaths by year
* List of expressions related to death
* Memento mori
* Near-death experience
* Origin-of-death myth
* Spiritual death
* Survivalism (life after death)
* Taboo on the dead
* Thanatology
* Yama
References
Bibliography
*
*
Further reading
*
*
*
*
*
*
*
*
External links
*
*
*
*
* Interviews with people dying in hospices, and portraits of them before, and shortly after, death.
* How the medical profession categorized causes of death.
* A biologist explains life and death in different kinds of organisms, in relation to evolution.
"Death" (video; 10:18)by Timothy Ferris, producer of the Voyager Golden Record for NASA. 2021
{{Authority control
Death,
Senescence