Postmortem interval changes (stages of death)

Livor mortis (

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

: ''līvor'' – "bluish color, bruise", ''mortis'' – "of death"), postmortem lividity (Latin: ''postmortem'' – "after death", ''lividity'' – "black and blue"), hypostasis (

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

: ὑπό, ''hypo'', meaning "under, beneath"; στάσις, ''stasis'', meaning "a standing") or suggillation, is the second stage of death and one of the signs of death. It is a settling of the

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in th ...

in the lower, or dependent, portion of the body postmortem, causing a purplish red discoloration of the skin. When the heart stops functioning and is no longer agitating the blood, heavy red blood cells sink through the

serum Serum may refer to: *Serum (blood), plasma from which the clotting proteins have been removed **Antiserum, blood serum with specific antibodies for passive immunity * Serous fluid, any clear bodily fluid * Truth serum, a drug that is likely to mak ...

by action of gravity. The blood travels faster in warmer conditions and slower in colder conditions. Livor mortis starts in 20–30 minutes, but is usually not observable by the human eye until two hours after death. The size of the patches increases in the next three to six hours, with maximum lividity occurring between eight and twelve hours after

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 brainstem, and brain ...

. The blood pools into the interstitial tissues of the body. The intensity of the color depends upon the amount of reduced haemoglobin in the blood. The discoloration does not occur in the areas of the body that are in contact with the ground or another object, in which

capillaries A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: ...

are compressed.

Applicability

Coroners can use the presence or absence of livor mortis as a means of determining an approximate time of death. It can also be used by

forensic Forensic science, also known as criminalistics, is the application of science to criminal and civil laws, mainly—on the criminal side—during criminal investigation, as governed by the legal standards of admissible evidence and crimin ...

investigators to determine whether or not a body has been moved. For instance, if the body is found lying

prone Prone position () is a body position in which the person lies flat with the chest down and the back up. In anatomical terms of location, the dorsal side is up, and the ventral side is down. The supine position is the 180° contrast. Etymolog ...

, but the pooling is present on the deceased's back, investigators can conclude that the body was originally positioned

supine In grammar, a supine is a form of verbal noun used in some languages. The term is most often used for Latin, where it is one of the four principal parts of a verb. The word refers to a position of lying on one's back (as opposed to ' prone', ...

. Among coroners and other investigators, such as homicide and forensic detectives, livor mortis is not considered an exact way to measure time of death, but rather as a way of approximating it. Livor mortis, along with algor mortis,

rigor mortis Rigor mortis (Latin: ''rigor'' "stiffness", and ''mortis'' "of death"), or postmortem rigidity, is the third stage of death. It is one of the recognizable signs of death, characterized by stiffening of the limbs of the corpse caused by chem ...

, and practices such as

forensic entomology Forensic entomology is the scientific study of the colonization of a dead body by arthropods. This includes the study of insect types commonly associated with cadavers, their respective life cycles, their ecological presences in a given environme ...

are frequently combined by investigators to more accurately pinpoint the estimated time of death.

Applicability

References

Further reading