Last updated: August 12, 2022

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Death is the cessation of life, but where life ends and death begins is not always clear. In medical contexts, a distinction is drawn between cardiopulmonary death (irreversible cessation of heartbeat and respiration) and brain death (irreversible cessation of all brain and brainstem function). Considering that pronouncing death is usually a physician's responsibility, it is important to know the signs of death and the differences between reversible and irreversible clinical death. If there is a delay before death has been pronounced or the events leading up to death are unclear, knowing irreversible postmortem changes also helps in determining both the manner and time of death. These changes may be of medical and/or legal interest and include rigor mortis, livor mortis, Tardieu spots, and decomposition. When pronouncing death, it is important to understand the events leading up to death, if it was expected or not, and to conduct a careful examination before declaring the death and its time. Since addressing family and friends after death is a very emotional and vital responsibility, clinicians should be prepared by having a clear approach for dealing with this situation. In addition, special documentation must be handled, including writing a death note, death summary, and death certificate. Important steps should also be considered if the patient is a potential donor candidate or if a medical examiner/coroner should be notified for further investigation and possibly an autopsy. Clinical autopsies are performed for the purpose of medical diagnosis and research, while forensic (i.e., medicolegal) autopsies are performed for the purpose of establishing the cause and manner of death, especially if there is evidence of foul play.

  • Death: An ambiguous term referring to the cessation of life.
  • Apparent death
    • Reduction of vital function to a minimum, creating the appearance of death without signs of certain death
    • Misdiagnosing apparent death as clinical death can have grave consequences such as postponing vital care, false alarms for organ donation, and unnecessary emotional stress for family members.
  • Clinical death (somatic/systemic death): a term for the cessation of respiration and circulation
    • May be reversible
    • Some descriptions may also consider the loss of brain activity as a component of clinical death.
  • Cardiopulmonary death: irreversible cessation of circulatory and respiratory functions
  • Brain death: irreversible, complete loss of function of the entire brain (including the brainstem), even if cardiopulmonary functions can be upheld by artificial life support
  • Intermediary life: the period of time between irreversible cardiopulmonary death and biological death
  • Biological death (molecular/cellular death)
    • Permanent and irreversible cellular damage with complete cessation of metabolic cell function
    • Tissue that has undergone biological death is unsuitable for transplantation.
  • Legal death
    • Recognition of a person's death under the law
    • Legal death comprises medically determined death (e.g., via a doctor's declaration of death) as well as the presumption under the law that a person is dead after a prolonged and unexplained absence with no signs of life (declaration of death in absentia).
  • Uniform determination of death act
    • In the US, legal provisions regarding death and the clinical examinations or legal investigations it may entail vary from state to state.
    • However, all states have adopted the “Uniform determination of death act” (1981), which specifies that the determination of death must be made in accordance with accepted medical standards and depends on either cardiopulmonary death or brain death.
  • Understanding the signs of clinical death is important for correctly declaring death.
  • Prematurely pronouncing death can have grave consequences, including neglecting potentially vital care, giving false alarms for organ donation, and unnecessary emotional stress for family members.
  • Uncertain signs of death must be considered in relation to certain and irreversible signs of death, such as cardiopulmonary and brain death.
  • If there is a delay before death has been pronounced or the events leading up to death are unclear, irreversible postmortem changes can help also in determining both the manner and time of death.

Cardiopulmonary death is the irreversible cessation of circulatory and respiratory functions. The following factors must be considered before making this determination:

  • Monitoring of the patient for a specific period of time to confirm continuous apnea, unconsciousness, and lack of circulation
  • Exclusion of factors that may be the cause of the cardiorespiratory arrest, such as:
  • No intention of beginning or continuing cardiopulmonary resuscitation (CPR); prohibition of any intervention that might restore cerebral blood flow [1]
  • Often synonymous with clinical death, but it is important to understand that clinical death is usually considered to be reversible
  • Definition: the irreversible, complete loss of function of the entire brain (including the brainstem), even if cardiopulmonary functions can be upheld by artificial life support
  • Practical steps for determination of brain death: The American Academy of Neurology has published a practical guide that consists of four steps. It cites specific measures and interpretations (e.g., limits of body temperature) that can be used to determine brain death, although not all of them are evidence-based.
  • Management

Clinical setting

  • Loss of brain function must be attributable to a specific cause (e.g., clinical or radiologic evidence of acute, severe damage to the CNS that is consistent with brain death).
  • Irreversible loss of brain function
  • Factors that may impede proper clinical judgment must be absent.
    • Complicating or mimicking conditions (e.g., electrolyte imbalances, locked-in syndrome)
    • Abnormal core temperature
    • Abnormal systolic blood pressure
    • Intoxication or effects of CNS-depressing drugs/neuromuscular blockade

Neurological examination

Neurological examination should confirm coma, brainstem areflexia, and apnea.

If spontaneous breathing is present, the medulla is intact. If the corneal reflex is present, the pons is intact. If the pupillary light reflex is present, the midbrain is intact.

Factors that falsely suggest cerebral function

  • Spontaneous or reflexive complex motor activity (e.g., repetitive leg movements)
  • False triggering of ventilator detection system for spontaneous breathing drive

Ancillary brain death tests


With the onset of death, all organisms undergo changes, mainly as a result of decomposition from putrefaction and autolysis, although external factors such as climate and location can also affect the state of a cadaver. Postmortem changes are signs of certain death that can provide information regarding the time, cause, mode, mechanism, and manner of death, as well as whether the location of the body corresponds to the place of death. These changes may be of medical and/or legal interest.

Early postmortem changes

  • Rigor mortis
    • The stiffening of the muscles after death, potentially with muscle shortening
    • Usually occurs within 1–2 hours of death
    • Starts to reside after about 24 hours
    • Caused by persistent attachment of actin to myosin due to lack of ATP
  • Livor mortis
    • Definition: purple-red discoloration of dependent areas of skin not exposed to pressure that begins 20–30 minutes after circulation stops due to blood settling under the force of gravity (hypostasis)
    • Occurrence
      • At least 30 minutes to 2 hours after onset of death [8]
      • Maximum observed at 6–12 hours [9]
    • Location: blood pools in areas of dependency under the force of gravity [10]
      • Person died lying face-up: back of the corpse
      • Hanging death: feet, fingertips and ear lobes [9]
      • Drowning: face, upper chest, hands, lower arms, feet, and calves [11]
      • Lividity is evident on the ear lobes and the nail beds
      • Also occurs in visceral organs (e.g., lungs)
    • Features
      • Redistribution: lividity can be altered up to 6 hours after onset of death [12]
      • Blanching: skin will turn white when applying pressure within the first ∼ 12 hours [13]
    • Color: the intensity of color depends on the amount of hemoglobin in the blood [14]
  • Injuries incompatible with life (e.g., incineration, decapitation)
  • Post mortem clots: separation of red blood cells and plasma creates clots of plasma that resemble “chicken fat” and blackish-red erythrocyte clots that resemble “currant jelly”

Livor mortis occurs approx. 30 minutes to 2 hours after the onset of death and is the first definite sign of death.

Late postmortem changes

  • Decomposition: breakdown of bone and tissue through aerobic and anaerobic processes
    • Insect and other animal activity can further advance decomposition; entomological investigations of larval development can help determine the time of death.
    • Casper's rule: a body will show similar marks of decomposition after one week of exposure to air, two weeks submerged underwater, and eight weeks of interment.
    • Autolysis: aerobic decomposition through endogenous acids and enzymes in the stomach, pancreas, etc.
    • Putrefaction
    • Mummification: Warm environments with extremely low humidity can cause bodies to mummify and resist decomposition.
    • Adipocere: Wet anaerobic environments (e.g., moors, bodies of water) may induce bacterial hydrolysis of fatty tissue (saponification), transforming tissue into a waxy substance called adipocere.
    • Venous patterning (marbling): prominent purple discoloration of subdermal vessels
    • Degloving: Thermal exposure, immersions, or advanced decomposition of skin and tissues result in degloving of skin (common in hands and feet).
  • Vibices: pale marks caused by pressure (e.g. from a rope in hanging death or generally from tight clothing, e.g., socks, belt, and bra)
  • Tardieu spots: dark pinpoint spots develop in dependent areas (e.g., in the legs of a hanged person due to increased gravitational pressure)
  • Laws regarding who is authorized to pronounce a person clinically and/or legally dead as well as who is authorized to order an investigation into the circumstances of death vary from state to state.
  • If a patient dies while under care, it is generally the physician's responsibility to examine the body to pronounce the death and record the time. Clinicians may also be called to the bedside for declaration of death.
  • In some states, registered nurses (especially in hospice settings) are authorized to pronounce death.
  • If no physician or registered nurse is readily available, a medical examiner or coroner is called to the scene to declare death.
  • Emergency response teams may pronounce a person “Dead on Arrival” (DOA) if certain criteria are met (e.g., obvious postmortem changes or injuries that are incompatible with life such as decapitation or evisceration of thoracic contents).
  • The specific procedures vary depending on the clinical scenario (e.g., cardiac death vs. brain death). Signs of death aid in diagnosing certain death and determining the time of death.


  • If called to declare death, determine:
    • If it was expected or not
      • If it was unexpected, efforts should be made to go immediately to the patient for assessment.
    • Who has already been informed
    • If family members are present
  • Assess the patient [15][16][17]
  • Pronounce the time of death
    • The official time of death is the time at which the examination confirms death.
    • If family or friends are present, determining the time of death via phone should be avoided. Instead, a watch or wall clock should be used.
  • Determine further information
    • The circumstances surrounding the patient's death
    • Whether organ donation is planned (if known). If a deceased individual is a potential donor candidate and had not refused to donate organs or tissue (e.g., in a living will), the proper organ donation organization/team should be notified immediately.
      • See “Organ donation considerations after death” for more details.
    • Whether an autopsy is planned or if a medical examiner/coroner should be notified to determine if an autopsy is necessary. Indications for notifying a medical examiner/coroner vary but may include any death associated with:
      • An unknown cause
      • Occurring within 24 hours of admission
      • Suspected homicide, suicide, poisoning, or drug overdose
      • Any indications of trauma
      • Any procedures or potential malpractice
      • SIDS
      • Any unusual circumstances
    • If there is reason to notify a medical examiner/coroner, he or she will determine if an autopsy is necessary. Neither the body nor medical equipment should be removed until the medical examiner/coroner has confirmed it is acceptable to do so.
  • Address family and friends: see below
  • Complete documentation: see below

If family or friends are present: [18]

  • Introduce yourself (e.g., “I am Dr. X. I am one of the doctors on the team taking care of “Mr. Y” or “I am covering for the doctors taking care of Mr. Y”) and explain why you are there (e.g., “I regret to inform you that Mr. Y has died”).
  • If possible, sit with the caregivers or family members.
  • Be direct in disclosing the death and avoid any euphemisms that may be ambiguous.
  • Offer condolences (e.g., “I'm so sorry for your loss”).
  • Offer them the opportunity to step out of the room for a few minutes while you pronounce the death.
  • Solicit extra help and information for families that are interested, including assisting in finding psychosocial counseling.
  • Helpful resources include:
  • Take some time to process the patient's death.
  • Your response to a patient's death will depend on the specific circumstances, e.g., whether the death was expected or unexpected and your relationship with the patient.
  • It is okay (and healthy) to express emotions.
  • Find a coping mechanism that works well for you.
    • Speak with family, friends, and other members of your support system.
    • Reflect on the care provided to the patient, particularly considering any positive contributions you have made to their care.
    • Depending on your relationship with the patient, sending condolences to a patient's family may help them to process the death.
    • If the death occurs in the middle of a busy shift and you do not have a lot of time to cope in the moment:
      • Make sure to take even a few minutes before seeing your next patient to process your emotions, while taking additional time after your shift.
      • Taking time to provide support to the patient's family can be helpful, if appropriate.
      • Consider checking in with a peer, senior resident, or attending.
      • Think about the ways you will be working to help your next patient(s).
  • Use this opportunity to reflect on end-of-life care in general (see “End-of-life issues” in “Principles of medical law and ethics”).

Physicians should follow local institutional protocols. They generally include:

  • In the US, the authority to sign death certificates varies from state to state. Generally, physicians are authorized to sign death certificates when the manner of death is natural, whereas in, e.g., violent or suspicious deaths, the authority lies with a coroner or medical examiner.
  • The U.S. Standard Certificate of Death provided by the CDC's National Center for Health Statistics (NCHS) records the following information:
    • To be provided/verified by the funeral director
      • Decedent's personal information (name, address, relations, race, education, occupation, etc.)
      • Place of death
      • Method and place of disposition
      • Funeral facility information
    • To be provided by the medical certifier

Reportable types of death

The initial postmortem examination may not provide conclusive information regarding the manner, cause, mechanism, or mode of death. In certain types of death, an investigation is required by law. The specific characteristics of death that require an investigation vary from state to state. Below is a selection of the types of death that most commonly require reporting:

  • Undetermined death
  • Suspicious/unusual/unnatural circumstances
  • Accident/casualty
  • Suicide
  • Violence
  • Homicide
  • Fetal/infant death
  • Sudden death when in apparent good health
  • Abortion/criminal abortion (maternal or fetal)
  • Death from injury
  • Therapeutic death or circumstances suggesting gross negligence in a healthcare setting
  • Death that may constitute threat to public health
  • Death in jail/police custody
  • Drug and/or chemical overdose or poisoning

Professionals involved in the investigation of death

  • Physician
    • Conducts postmortem examination
    • Determines the cause, time, and manner of deaths that occurred under natural circumstances; declares death; issues death certificates
    • Notifies local death investigation office if the type of death requires reporting (e.g., if it occurs under unnatural circumstances)
  • Coroner
    • Elected government official tasked with running the investigation to determine the cause, time, and manner of deaths that occurred under unexpected, violent, and suspicious circumstances or in the absence of a physician
    • Declares death; issues death certificates; initiates inquests; requests autopsies; qualifications, functions, and authority vary from state to state; does not require medical training
  • Medical examiner: medically trained government official qualified to perform autopsies; otherwise similar functions and authority as coroner
  • Forensic pathologist: establishes cause of death and performs autopsy upon the request of the medical examiner or coroner
  • Death investigator: assists the medical examiner/coroner in investigating deaths, focusing on the collection of information on the decedent and guiding the investigation process.


  • A legal inquiry before a coroner or medical examiner to establish the identity of the decedent and the time, place, cause, and manner of death.
  • Often involves a jury; inquiries are conducted almost exclusively in the event of deaths taking place under unexpected, violent, or mysterious circumstances.

The first step in investigating a death is determining the manner by which a person died. If the manner of death is determined to be natural, a further investigation is not legally obligatory, while unnatural manners of death elicit an inquiry into the precise circumstances. The manner of death is distinct from the mode, cause, and mechanism of death in so far as the manner is the root cause of how the death occurred (e.g., “homicide” involving an axe attack), while the cause is the disease or injury that causes death (e.g., an “axe wound”), the mechanism is the physiological derangement that causes death (e.g., “exsanguination” due to an axe wound), and mode is the abnormal physiological state in an individual at the time of death (coma = failure of brain function, syncope = failure of heart function, asphyxia = failure of respiratory system; e.g., “coma” from axe wound). The manner of death is of particular importance because of the legal consequences that inevitably follow any unnatural manner of death.

  • Natural manner of death
    • Due (nearly) exclusively to disease and/or age
    • Patient history characteristic of a specific cause of death
    • Clear and objectifiable findings characteristic of underlying disease
    • No evidence of third-party interference in the course of the disease
  • Unnatural manners of death: death caused by external events or a third party
    • Accident: death from injury or poisoning without evidence of third party intent to kill or cause harm
    • Suicide: death from intentional, self-inflicted injury or poisoning for the purpose of causing self-harm or death
    • Homicide: death from intentional injury or poisoning committed by another person for the purpose of causing fear, harm, or death. Intent is a common element, but it is not required for classification.
  • Could not be determined: applied to deaths in which the manner could not be determined even after consideration of all information available
  • Pending investigation: if determination of the manner of death depends on further information


  • Close examination of a body to determine the cause of death; typically involves dissection of the body
  • Many states require that a pathologist performs the autopsy.
  • However, in some states, autopsies may also be performed by medical examiners without a degree in pathology.

Clinical autopsy

  • Purposes
    • Medical investigation into the cause of a natural death (i.e. does not consider the manner of death) and any pre-existing illnesses
    • Diagnosis of diseases that can only be confirmed postmortem (e.g., Parkinson's disease) or where antemortem efforts failed
    • Confirmation that the diagnosis made before death was correct and that the treatments administered were reasonable
    • Requested by next of kin
    • Research
  • Authorization
    • In life: patient or healthcare surrogate
    • Postmortem: next of kin

Forensic autopsy

  • Purposes
    • Medicolegal investigation into the circumstances of unexplained or (possibly) unnatural deaths
    • Establishing the identity of the decedent and the time, place, and manner of death
    • Collect forensic evidence
    • Reconstruct a crime or accident
  • Authorization
  • Characteristics of death that may require a forensic autopsy

Signs of vitality (vital reactions)

Signs of vitality (not to be confused with vital signs) are signs that a body was still alive at the time of having sustained damage as opposed to the damage having occurred postmortem.

Signs of vitality provide clues that damage to an organism occurred before the onset of death.

Supravital reactions

Supravital reactions are certain physical functions that persist for some time after the onset of death. They provide specific clues regarding the time of death.

  • Up to 8 hours after onset of death: skeletal musculature
    • Up to 8 hours postmortem: Mechanical stimulation causes slight idiomuscular bulging that may persist for up to 24 hours.
    • 3–5 hours postmortem: Mechanical stimulation causes pronounced reversible idiomuscular bulging.
    • 1.5–2.5 hours postmortem: Zsako's muscle phenomenon, i.e., mechanical stimulation causes propagated excitation
  • Up to 17 hours: pupillary response
  • Up to 80 hours: motile sperm cells

Evidence of live birth

The condition of the lungs and the gastrointestinal tract can provide evidence of whether an infant was alive at birth or stillborn.

  1. Miletich JJ, Lindstrom TL. An Introduction to the Work of a Medical Examiner. ABC-CLIO ; 2010
  2. Tsokos M. Forensic Pathology Reviews. Springer Science & Business Media ; 2007
  3. Post-Mortem Hypostasis. Updated: January 1, 2013. Accessed: October 9, 2017.
  4. Gannon K, Gilbertson DL. Case Studies in Drowning Forensics. CRC Press ; 2014
  5. Hammer R, Moynihan B, Pagliaro EM. Forensic Nursing. Jones & Bartlett Publishers ; 2011
  6. Prahlow J. Forensic Pathology for Police, Death Investigators, Attorneys, and Forensic Scientists. Humana Press ; 2010
  7. Noriko T. Immunohistochemical studies on postmortem lividity. Forensic Sci Int. 1995; 72 (3): p.179-189.
  8. Naik SB. Death in the hospital: Breaking the bad news to the bereaved family.. Indian journal of critical care medicine. 2013; 17 (3): p.178-81. doi: 10.4103/0972-5229.117067 . | Open in Read by QxMD
  9. International Guidelines for the Determination of Death. Updated: October 1, 2012. Accessed: April 14, 2021.
  10. Greer DM, Shemie SD, Lewis A, et al. Determination of Brain Death/Death by Neurologic Criteria: The World Brain Death Project.. JAMA. 2020; 324 (11): p.1078-1097. doi: 10.1001/jama.2020.11586 . | Open in Read by QxMD
  11. Nikas NT, Bordlee DC, Moreira M. Determination of Death and the Dead Donor Rule: A Survey of the Current Law on Brain Death. J Med Philos. 2016; 41 (3): p.237-256. doi: 10.1093/jmp/jhw002 . | Open in Read by QxMD
  12. Gardiner D, Shemie S, Manara A, Opdam H. International perspective on the diagnosis of death. Br J Anaesth. 2012; 108 : p.i14-i28. doi: 10.1093/bja/aer397 . | Open in Read by QxMD
  13. Kasper DL, Fauci AS, Hauser SL, Longo DL, Lameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. McGraw-Hill Education ; 2015
  14. Wijdicks EF, Varelas PN, Gronseth GS, Greer DM, American Academy of Neurology. Evidence-based guideline update: determining brain death in adults: report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2010; 74 (23): p.1911-1918. doi: 10.1212/WNL.0b013e3181e242a8 . | Open in Read by QxMD
  15. Devastating brain injuries: assessment and management part I: overview of brain death. Updated: February 1, 2009. Accessed: February 19, 2017.
  16. Young GB. Diagnosis of brain death. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate.§ionRank=1&anchor=H2#H2.Last updated: May 27, 2015. Accessed: February 19, 2017.
  17. Schofield GM, Urch CE, Stebbing J, Giamas G. When does a human being die?. QJM. 2014; 108 (8): p.605-609. doi: 10.1093/qjmed/hcu239 . | Open in Read by QxMD
  18. Scott JB, Gentile MA, Bennett SN, Couture M, MacIntyre NR. Apnea testing during brain death assessment: a review of clinical practice and published literature. Respir Care. 2013; 58 (3): p.532-538. doi: 10.4187/respcare.01962 . | Open in Read by QxMD

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