Postmortem Changes

Article Author:
Abdulaziz Almulhim

Article Editor:
Ritesh Menezes

Editors In Chief:
Ron Feller
Grant Goold
Kyle Cohen

Managing Editors:
Avais Raja
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Khalid Alsayouri
Frank Smeeks
Kristina Soman-Faulkner
Radia Jamil
Patrick Le
Sobhan Daneshfar
Anoosh Zafar Gondal
Saad Nazir
William Gossman
Pritesh Sheth
Hassam Zulfiqar
Navid Mahabadi
Steve Bhimji
John Shell
Matthew Varacallo
Heba Mahdy
Ahmad Malik
Mark Pellegrini
James Hughes
Beata Beatty
Nazia Sadiq
Hajira Basit
Phillip Hynes
Tehmina Warsi

3/22/2019 8:46:02 AM


Postmortem changes constitute the natural progression of the body’s decomposition after death, beginning at the cellular level. The process involves complex cellular and biological phenomena. The changes that commence immediately after death continue to occur over a prolonged period at different rates for different organs. The onset and extent of these changes are affected by multiple intrinsic and extrinsic factors. The rates are not precise and differ from one geographical region to another, and also differ in the same geographical region from one season to another. An understanding of the postmortem changes is essential for the estimation of the postmortem interval (PMI) or time since death, one of the primary objectives of the forensic autopsy. The timings of the appearance of the various postmortem changes mentioned in this brief overview of postmortem changes are only guidelines pertaining to tropical climates unless otherwise specified and should never be considered as absolute.  

Issues of Concern


The rate of postmortem changes is either accelerated or decelerated by various intrinsic and extrinsic factors. Intrinsic factors involving the subject that affect postmortem changes primarily include body mass and the surface area of the body. Extrinsic factors that affect postmortem changes primarily include the subject’s clothing and insulation, the environment of the death scene, and storage of the body after death.[1][2][3][4] These factors either accelerate or decelerate the onset and extent of postmortem changes. Some of the factors that accelerate the rate of postmortem changes include a high-fat content of the subject, sepsis or underlying infection as the direct or contributing cause of death, and the presence of open wounds. Some of the factors that decelerate the rate of postmortem changes include freezing ambient temperatures, scantily dressed or naked subject, and storage of the body in a cold chamber shortly after death.  


Postmortem changes are classified based on their order of appearance into immediate, early and late postmortem changes.

Immediate Postmortem Changes

"Immediate postmortem changes" or "rapid changes after death" relate to the cessation of bodily functions including the respiratory, circulatory, and nervous systems. These changes are specifically the "signs of death" or "indications of death." In brief, death is considered to have occurred when the vital functions of the body have irreversibly ceased. 

Respiration completely stops after death resulting in loss of respiratory movements and breathing sounds. The feather test and mirror test are a couple of traditional tests used to confirm this. However, these tests are quite unreliable. Circulatory stoppage results in a loss of pulse, which can also be confirmed by a flat electrocardiogram (ECG) in a hospital setting. The absence of respiratory and cardiac sounds on auscultation over a period of 5 minutes indicates a sign of death as advocated by expert clinicians. The finding of the break-up of the columns of blood in the retinal blood vessels (retinal vascular segmentation) on ophthalmoscopy confirms stoppage of circulation and is one of the earliest indications of death. Cessation of nervous system functions results in the loss of sensory and motor functions and reflexes. The muscles begin to become flaccid with lose of tone. Pupils also dilate as a result of this. In a hospital setting, a flat electroencephalogram (EEG) is confirmatory of loss of electrical activity in the brain.  

Early Postmortem Changes

Three early postmortem changes that occur while the body is still in the fresh stage, before the breakdown of soft tissues, namely algor mortis, livor mortis, and rigor mortis are of forensic significance.[5]

The eye changes that occur during the early postmortem period include corneal turbidity/opacity and tache noire formation. The intraocular tension progressively falls to nil in about 2 hours after death, although this is disputable.

Algor mortis is the postmortem cooling of body temperature until it equalizes the temperature of the surrounding environment. The rate of cooling lags initially, then becomes linear before slowing down again as it approaches the ambient temperature, giving a sigmoid-shaped curve when graphically represented. The ambient temperature is a critical factor that affects the rate of postmortem cooling of the body. Postmortem cooling of the body continues for about 6 hours after death, and the rate of cooling is primarily dependent on the difference in body temperature at the time of death and the temperature of its surroundings. The rate of cooling will hasten in a body immersed in water, naked body, and a thin body. The rate of cooling will be slower in a well-clothed body and an obese body. A prudent forensic pathologist will not estimate the time since death based on the single criterion of algor mortis as the rate of postmortem cooling of the body is affected by multiple variables. 

Livor mortis, also known as postmortem hypostasis or postmortem lividity, is a passive process of blood accumulating within the blood vessels in the dependent parts of the body as a result of gravity, causing a discoloration of the skin that varies from pink to dark purplish. It begins to be apparent about an hour after death, is well formed in about 3 to 4 hours after death, and gets fixed in about 6 to 8 hours after death. However, it is worth noting that the timing of livor mortis is highly variable. Hemolysis leads to fixation of lividity. Once fixed, lividity does not shift its distribution when the position of the body changes. The dermal manifestation of postmortem lividity may be absent in the severely anemic or in those who have died of severe hemorrhage. It may not be apparent in the dark-skinned.

Livor mortis should be differentiated from a contusion or bruise, which occurs as a result of blood vessel rupture from blunt force impact and exsanguination of blood into the surrounding tissues.

Rigor mortis (postmortem rigidity) is the stiffening of the muscles of the corpse due to depletion of adenosine triphosphate (ATP) after death with the subsequent build-up of lactate in muscle tissue, resulting in an inability to release the actin-myosin bond. This postmortem muscle change appreciated grossly follows the initial phase of primary flaccidity of muscles and is itself followed by the secondary flaccidity of muscles that coincides with the beginning of putrefactive changes. The process of rigor mortis uniformly involves all muscles of the body. However, it is first apparent generally in smaller muscles such as the jaw and the eyelids due to a quicker depletion of ATP relative to larger muscles in the trunk and limbs. Rigor mortis occurs in both voluntary and involuntary muscles including the cardiac muscle. It is first evident in the facial muscles at 1 to 4 hours after death. The gelling of the muscle proteins is apparent as muscle stiffening in about 6 hours after death in the rest of the muscles and is complete in about 12 hours after death. This rigidity of the muscles lasts for about another 12 hours or so. The body then returns to a flaccid state after the enzymatic breakdown of the binding sites of actin and myosin. The rate at which rigor mortis passes off will be rapid in a hot environment as the onset of putrefaction is hastened in such an environment. Cold temperatures lengthen the duration of rigor.  

In brief, postmortem changes in the muscles include:

  • Primary flaccidity of the muscles
  • The rigidity of the muscles (rigor mortis)
  • Secondary flaccidity of the muscles

Rigor mortis of the arrector pili muscle attached to the base of a hair follicle is also responsible for the phenomenon of cutis anserina (cutis anserine), otherwise known as postmortem goosebumps. Rigor mortis needs to be distinguished from cadaveric spasm/instantaneous rigor, which is an immediate contraction of a small group of muscles at the instance of death, seen in scenarios of violent death like in the case of drowning. 

Late Postmortem Changes


Two mechanisms are involved in decomposition: autolysis and putrefaction.[6] Although decomposition begins soon after death in the form of autolysis, the macroscopic changes brought about by decomposition become apparent much later when putrefaction occurs.

Autolysis is a process that occurs due to leakage of hydrolytic cellular enzymes from cells after death. The changes that occur in this process are mainly on a microscopic rather than a macroscopic level.[7] Internally, autolytic changes are most prominent in the pancreas and other organs with a high concentration of cellular enzymes. In comparison, the prostate and the non-gravid uterus take a longer duration of time to decompose.

The leakage of cellular contents also leads to a suitable environment for microbes such as bacteria, fungi, and protozoa, normally present in the human microbiota, to grow and degrade surrounding tissues, which is known as the process of putrefaction.[8][9]

Unlike autolytic changes, putrefactive changes are visible on a macroscopic level as discoloration of skin or bloating of body parts such as the face, abdomen, breast, and scrotum. It can appear in various forms such as putrefactive fluids and putrefactive gases.


There are five stages of decomposition, namely fresh, bloated, active decay, advanced decay, and skeletal stage.[10] These stages may occur simultaneously in different parts of the same corpse, and it may be difficult for a forensic pathologist to label the state of the corpse with a single stage.[1]

The fresh stage is the immediate period following death in which autolysis occurs. Algor mortis, livor mortis, and rigor mortis are apparent in this stage.

The earliest external sign of putrefaction is the greenish discoloration of the skin of the anterior abdominal wall in the right iliac fossa region. In this region of the abdomen, the caecum, loaded with semi-solid intestinal content and commensal gut bacteria lies quite superficial. This greenish discoloration of the skin results from the formation of sulfhemoglobin facilitated by the commensal intestinal bacteria that invade the tissues after death. This skin discoloration in the right iliac fossa region appears in about 18 hours after death. In temperate climates, this greening may first appear 2 to 3 days after death. The ambient temperature affects the speed of onset of putrefaction and its rate of progression.

The blowflies (Calliphoridae) and flesh flies (Sarcophagidae) are often the first insects to be attracted to a dead body. In brief, the invasion of the body by flies and the life cycle of flies (oviposition, hatching of eggs, feeding activity of larvae or maggots, the transformation of maggots to adult flies) coincide primarily with the bloated and decay stages of decomposition. The flies may even be attracted to a dead body towards the end of the fresh stage.

In the bloated stage, body parts, including organs and soft tissues swell due to the accumulation of putrefactive gases or other decompositional products from the putrefaction process. It usually starts in the abdomen and then slowly affects other parts including the face, breasts, and genitals.[11][12] Also during this stage, skin changes occur such as blisters and slippage. Skin slippage at the extremities is known as degloving. Moreover, the phenomenon of marbling is also present during this stage, where blood vessels are visible on the skin as greenish-black streaks and eventually results in skin discoloration ranging from green to black.[4] These postmortem changes are apparent in about 24 to 48 hours after death.

Active decay is a stage where putrefaction accelerates after bloating. Postmortem purging where putrefactive body fluids are forced out of body orifices is observed during this stage of decay. The detachment of hair or hair sloughing and black discoloration of ruptured skin are observed.

Advanced decay, also called black putrefaction or late decay is a stage where bones begin to get exposed, and the body assumes a "caved in" appearance. Degradation-resistant tissue such as hair (although already sloughed) and cartilage are spared up to this stage.[11][13]

Skeletal stage, also called dry remains stage or skeletonization, begins when bone exposure is extensive, but the bone is yet to breakdown.[13][14] Remaining dried skin, cartilage, and tendons are minimal in this stage.[15] Decomposition significantly slows down at this stage, and it takes years or decades for the skeletal remains to disintegrate.

The literature also reports differential decomposition involving mummification or adipocere formation.


Mummification results from tissue desiccation and is a phenomenon that occurs when the corpse is in an environment that is hot and dry. The skin of the corpse becomes dark, dry and appears leathery in appearance.[16] Overall the body appears parched; this preserves the corpse for a longer period. It can occur to the corpse as a whole, or in localized areas such as the extremities or the tongue.


Adipocere is yellowish to gray like colored waxy substance that can preserve the corpse as a whole or some parts of it. Adipocere formation in the buccal pad of fat will retain the outline of the cheeks. Unlike mummification, the process of adipocere formation occurs in corpses in environments that are high in moisture. Anaerobic conditions, such as a flooded burial or submersion in water facilitate adipocere formation. The process primarily involves hydrolysis and hydrogenation of body fats to fatty acids and soaps and the formation of adipocere.[17][18][19] Although adipocere formation is reported to have occurred as early as about 3 weeks after death, in most cases, it becomes apparent only months after death. 

Clinical Significance

Although early and late postmortem changes are heralded as definite signs of death in traditional textbooks, in practical reality, they are not criteria in considering the diagnosis of death. Nevertheless, the immediate postmortem changes are clinically significant in diagnosing death. In the context of the diagnosis of death, the condition known as suspended animation or apparent death should also merit consideration. Suspended animation is a condition where the person appears to be dead due to the fact that the vital conditions are at such a low pitch as to be minimum compatible with life. This condition may occur in a person fished out of water or hypothermia. In such situations, doctors erroneously declaring a patient dead is a huge embarrassment. Nonetheless, the literature contains reports of cases of wrongful declaration of death.[20]

The early and late postmortem changes are significant from a forensic perspective in primarily estimating the time since death or PMI.


Post-mortem interval (PMI) is the time that has passed since the death of a person until found, is an essential tool in forensic investigations as providing an estimated time since death, is pivotal in judicial cases and can even either incriminate or acquit a suspect.

Understanding the appearance and progression of the postmortem changes is essential in estimating the PMI.[5][21] The earlier a corpse is found, the more accurate the PMI estimation is likely to be. Once a corpse undergoes putrefaction, PMI can only be provided as a rough range as many variables affect the rate of these changes.[22] Estimation of PMI should not be based solely upon a single postmortem change, and instead, all the postmortem changes should be considered collectively in forming an opinion of the time since death. A sensible forensic pathologist will never provide an assessment of the specific "time of death," but will only provide a range of estimation of the "time since death." 

Secondly, a doctor should also be aware of the postmortem changes to avoid misinterpretation of these findings as signs of physical violence or unnatural death. It is not uncommon for the emotionally charged legal heirs of the deceased or members of the lay public to wrongly interpret postmortem lividity for a contusion, especially in instances where death is not witnessed by them, despite assertions from a forensic pathologist.

Incorrect opinions from a misinterpretation of postmortem changes for traumatic injuries during the postmortem examination may mislead the investigation in the wrong direction leading to unnecessary inquiries that may even end up in the miscarriage of justice.


Two specific reasons for a doctor to know the progress of postmortem changes include:

  • To recognize the normal changes that occur after death as distinct from traumatic injuries thus avoiding misinterpretation of postmortem changes for signs of violence [for example, livor mortis (postmortem change) that normally occurs in the early postmortem period should not be subject to incorrect interpretation as a contusion (blunt force trauma)]
  • To estimate the time since death based on the postmortem changes

Interested in Participating?

We are looking for contributors to author, edit, and peer review our vast library of review articles and multiple choice questions. In as little as 2-3 hours you can make a significant contribution to your specialty. In return for a small amount of your time, you will receive free access to all content and you will be published as an author or editor in eBooks, apps, online CME/CE activities, and an online Learning Management System for students, teachers, and program directors that allows access to review materials in over 500 specialties.

Improve Content - Become an Author or Editor

This is an academic project designed to provide inexpensive peer-reviewed Apps, eBooks, and very soon an online CME/CE system to help students identify weaknesses and improve knowledge. We would like you to consider being an author or editor. Please click here to learn more. Thank you for you for your interest, the StatPearls Publishing Editorial Team.

Postmortem Changes - Questions

Take a quiz of the questions on this article.

Take Quiz
How long does rigor mortis last after death?

Click Your Answer Below

Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.

Sign Up
Emergency medical services are called by a nurse to see a 62-year-old patient who is not responding. Upon arrival, the patient has expired. Closer examination reveals patchy postmortem lividity on the back of the trunk and flaccid limbs. Based on these examination findings, when did the patient expire?

Click Your Answer Below

Would you like to access teaching points and more information on this topic?

Improve Content - Become an Author or Editor and get free access to the entire database, free eBooks, as well as free CME/CE as it becomes available. If interested, please click on "Sign Up" to register.

Purchase- Want immediate access to questions, answers, and teaching points? They can be purchased above at Apps and eBooks.

Sign Up

Postmortem Changes - References


Adlam RE,Simmons T, The effect of repeated physical disturbance on soft tissue decomposition--are taphonomic studies an accurate reflection of decomposition? Journal of forensic sciences. 2007 Sep;     [PubMed]
Poloz YO,O'Day DH, Determining time of death: temperature-dependent postmortem changes in calcineurin A, MARCKS, CaMKII, and protein phosphatase 2A in mouse. International journal of legal medicine. 2009 Jul;     [PubMed]
Sutherland A,Myburgh J,Steyn M,Becker PJ, The effect of body size on the rate of decomposition in a temperate region of South Africa. Forensic science international. 2013 Sep 10;     [PubMed]
Megyesi MS,Nawrocki SP,Haskell NH, Using accumulated degree-days to estimate the postmortem interval from decomposed human remains. Journal of forensic sciences. 2005 May;     [PubMed]
Reddy K,Lowenstein EJ, Forensics in dermatology: part I. Journal of the American Academy of Dermatology. 2011 May;     [PubMed]
Cockle DL,Bell LS, The environmental variables that impact human decomposition in terrestrially exposed contexts within Canada. Science     [PubMed]
Shirley NR,Wilson RJ,Jantz LM, Cadaver use at the University of Tennessee's Anthropological Research Facility. Clinical anatomy (New York, N.Y.). 2011 Apr;     [PubMed]
Zhou C,Byard RW, Factors and processes causing accelerated decomposition in human cadavers - An overview. Journal of forensic and legal medicine. 2011 Jan;     [PubMed]
Paczkowski S,Schütz S, Post-mortem volatiles of vertebrate tissue. Applied microbiology and biotechnology. 2011 Aug;     [PubMed]
Dekeirsschieter J,Verheggen FJ,Gohy M,Hubrecht F,Bourguignon L,Lognay G,Haubruge E, Cadaveric volatile organic compounds released by decaying pig carcasses (Sus domesticus L.) in different biotopes. Forensic science international. 2009 Aug 10;     [PubMed]
Gebhart FT,Brogdon BG,Zech WD,Thali MJ,Germerott T, Gas at postmortem computed tomography--an evaluation of 73 non-putrefied trauma and non-trauma cases. Forensic science international. 2012 Oct 10;     [PubMed]
Sharanowski BJ,Walker EG,Anderson GS, Insect succession and decomposition patterns on shaded and sunlit carrion in Saskatchewan in three different seasons. Forensic science international. 2008 Aug 6;     [PubMed]
Matuszewski S,Bajerlein D,Konwerski S,Szpila K, An initial study of insect succession and carrion decomposition in various forest habitats of Central Europe. Forensic science international. 2008 Sep 18;     [PubMed]
Swann LM,Forbes SL,Lewis SW, Analytical separations of mammalian decomposition products for forensic science: a review. Analytica chimica acta. 2010 Dec 3;     [PubMed]
Schotsmans EM,Van de Voorde W,De Winne J,Wilson AS, The impact of shallow burial on differential decomposition to the body: a temperate case study. Forensic science international. 2011 Mar 20;     [PubMed]
Forbes SL,Stuart BH,Dent BB, The effect of the burial environment on adipocere formation. Forensic science international. 2005 Nov 10;     [PubMed]
Notter SJ,Stuart BH,Rowe R,Langlois N, The initial changes of fat deposits during the decomposition of human and pig remains. Journal of forensic sciences. 2009 Jan;     [PubMed]
Ubelaker DH,Zarenko KM, Adipocere: what is known after over two centuries of research. Forensic science international. 2011 May 20;     [PubMed]
Kaliszan M,Hauser R,Kernbach-Wighton G, Estimation of the time of death based on the assessment of post mortem processes with emphasis on body cooling. Legal medicine (Tokyo, Japan). 2009 May;     [PubMed]
Myburgh J,L'Abbé EN,Steyn M,Becker PJ, Estimating the postmortem interval (PMI) using accumulated degree-days (ADD) in a temperate region of South Africa. Forensic science international. 2013 Jun 10;     [PubMed]
Lee Goff M, Early post-mortem changes and stages of decomposition in exposed cadavers. Experimental & applied acarology. 2009 Oct     [PubMed]
Verdú F,Francès F,Castelló A, Sure he's dead? Be wise. Journal of forensic and legal medicine. 2013 Oct     [PubMed]


The intent of StatPearls is to provide practice questions and explanations to assist you in identifying and resolving knowledge deficits. These questions and explanations are not intended to be a source of the knowledge base of all of medicine, nor is it intended to be a board or certification review of EMS-Paramedic. The authors or editors do not warrant the information is complete or accurate. The reader is encouraged to verify each answer and explanation in several references. All drug indications and dosages should be verified before administration.

StatPearls offers the most comprehensive database of free multiple-choice questions with explanations and short review chapters ever developed. This system helps physicians, medical students, dentists, nurses, pharmacists, and allied health professionals identify education deficits and learn new concepts. StatPearls is not a board or certification review system for EMS-Paramedic, it is a learning system that you can use to help improve your knowledge base of medicine for life-long learning. StatPearls will help you identify your weaknesses so that when you are ready to study for a board or certification exam in EMS-Paramedic, you will already be prepared.

Our content is updated continuously through a multi-step peer review process that will help you be prepared and review for a thorough knowledge of EMS-Paramedic. When it is time for the EMS-Paramedic board and certification exam, you will already be ready. Besides online study quizzes, we also publish our peer-reviewed content in eBooks and mobile Apps. We also offer inexpensive CME/CE, so our content can be used to attain education credits while you study EMS-Paramedic.