death death death is the irreversible cessation of all biological functions that sustain an organism. for organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including the brainstem, and brain death is sometimes used as a legal definition of death. the remains of a former organism normally begin to decompose shortly after death. death is an inevitable process that eventually occurs in all organisms. some organisms, such as turritopsis dohrnii, are biologically immortal. however, they can still die from other means than aging. the human skull is used universally as a symbol of death. figuring out when someone is dead has been a problem. initially, there was the definition of death when breathing and the heartbeat ceased. however, the spread of cpr no longer meant it was irreversible. brain death was the next option, which fractured between different definitions. some people believe that all brain functions must cease. some believe that even if the brainstem is still alive, their personality and identity are dead, so therefore, they should be entirely dead. death is generally applied to whole organisms; the similar process seen in individual components of an organism, such as cells or tissues, is necrosis. something that is not considered an organism, such as a virus, can be physically destroyed but is not said to die, as a virus is not considered alive. as of the early 21st century, 56 million people die per year. the most common reason is cardiovascular disease, which is a disease that affects the heart. many cultures and religions have the idea of an afterlife and also may hold the idea of judgment of good and bad deeds in one's life. there may also be different customs for honoring the body, such as a funeral, cremation, or sky burial. death is actively trying to be cured by a group of scientists known as biogerontologists, through seeking to do the same as biologically immortal organisms do and applying a similar means to humans. however, as humans do not have the means to apply this to themselves, they have to use other ways to reach the maximum lifespan for a human, such as calorie reduction, dieting, and exercise. diagnosis world health organization estimated number of deaths per million persons in 2012 1.054–4.598 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 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. defining life to define death one of the challenges in defining death is in distinguishing it from life. as a point in time, death seems to refer to the moment when life ends. determining when death has occurred is difficult, as cessation of life functions is often not simultaneous across organ systems. 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. 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 organismic functioning and human death, which refers to irreversible loss of personhood. more specifically, death occurs when a living entity experiences irreversible cessation of all functioning. as it pertains to human life, death is an irreversible process where someone loses their existence as a person.a flower, a skull and an hourglass stand for life, death, and time in this 17th-century painting by philippe de champaigne definition of death by heartbeat and breath historically, attempts to define the exact moment of a human's death have been subjective or imprecise. death was defined as the cessation of heartbeat (cardiac arrest) and breathing, but the development of cpr and prompt defibrillation 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 (cdd). proponents of the cdd believe this definition is reasonable because a person with permanent loss of circulatory and respiratory function should be considered dead. 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 fast enough, the person could be revived. thus, the arguments for and against the cdd boil down to defining the actual words "permanent" and "irreversible," which further complicates the challenge of defining death. furthermore, events 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. brain death today, where a definition of the moment of death is required, doctors and coroners usually turn to "brain death" or "biological death" to define a person as being dead; 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 are used to tell the difference. the category of "brain death" is seen as problematic by some scholars. for instance, dr. franklin miller, a senior faculty member at the department of bioethics, national institutes of health, notes: "by the late 1990s... the equation of brain death with death of the human being was increasingly challenged by scholars, based on evidence regarding the array of biological functioning displayed by patients correctly diagnosed as having this condition who were maintained on mechanical ventilation for substantial periods of time. these patients maintained the ability to sustain circulation and respiration, control temperature, excrete wastes, heal wounds, fight infections and, most dramatically, to gestate fetuses (in the case of pregnant "brain-dead" women)."french – 16th-/17th-century ivory pendant, monk and death, recalling mortality and the certainty of death (walters art museum) while "brain death" is viewed as problematic by some scholars, there are 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 in a vegetative state or coma, in that the former situation describes a state that is beyond recovery. eegs can detect spurious electrical impulses, while certain drugs, hypoglycemia, hypoxia, or hypothermia can suppress or even stop brain activity temporarily; because of this, hospitals have protocols for determining brain death involving eegs at widely separated intervals under defined conditions. neocortical brain death people maintaining that only the neo-cortex of the brain is necessary for consciousness sometimes argue that only electrical activity should be considered when defining death. eventually, the criterion for death may be the permanent and irreversible loss of 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. even by whole-brain criteria, the determination of brain death can be complicated. total brain death at present, in most places, the more conservative definition of death – 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 the past, the adoption of this whole-brain definition was a conclusion of the president's commission for the study of ethical problems in medicine and biomedical and behavioral research in 1980. they concluded that this approach to defining death sufficed in reaching a uniform definition nationwide. a multitude of reasons was presented to support this definition, including uniformity of standards in law for establishing death, consumption of a family's fiscal resources for artificial life support, and legal establishment for equating brain death with death to proceed with organ donation. problems in medical practice timeline of postmortem changes (stages of death).aside from the issue of support of or dispute against brain death, there is another inherent problem in this categorical definition: the variability of its application in medical practice. in 1995, the american academy of neurology (aan) established the criteria that became the medical standard for diagnosing neurologic death. at that time, three clinical features had to be satisfied to determine "irreversible cessation" of the total brain, including coma with clear etiology, cessation of breathing, and lack of brainstem reflexes. this criteria was updated again, most recently in 2010, but substantial discrepancies remain across hospitals and medical specialties. donations the problem of defining death is especially imperative as it pertains to the dead donor rule, which could be understood as one of the following interpretations of the rule: there must be an official declaration of death in a person before starting organ procurement, or that organ procurement cannot result in the death of the donor. a great deal of controversy has surrounded the definition of death and the dead donor rule. advocates of the rule believe that the rule is legitimate in protecting organ donors while also countering any moral or legal objection to organ procurement. critics, on the other hand, believe that the rule does not uphold the best interests of the donors and that the rule does not effectively promote organ donation. signs signs of death or strong indications that a warm-blooded animal is no longer alive are: respiratory arrest (no breathing) cardiac arrest (no pulse) brain death (no neuronal activity) the stages that follow after death are: pallor mortis, paleness which happens in 15–120 minutes after death 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 livor mortis, a settling of the blood in the lower (dependent) portion of the body putrefaction, the beginning signs of decomposition decomposition, the reduction into simpler forms of matter, accompanied by a strong, unpleasant odor. skeletonization, the end of decomposition, where all soft tissues have decomposed, leaving only the skeleton. fossilization, 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 jurisdictions. most countries follow the whole-brain death criteria, where all functions of the brain must have completely ceased. however, in other jurisdictions, some follow the brainstem version of brain death. afterward, a death certificate is issued in most jurisdictions, either by a doctor or by an administrative office, upon presentation of a doctor's declaration of death. misdiagnosis the premature burial, antoine wiertz's painting of a man buried alive, 1854 there are many anecdotal references to people being declared dead by physicians and then "coming back to life," sometimes days later in their coffin or when embalming procedures are about to begin. from the mid-18th century onwards, there was an upsurge in the public's fear of being mistakenly buried alive 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