Also known as: Livor mortis or postmortem lividity or hypostasis
To see a body with Livor mortis, click here. (It's not a gruesome picture - no face shown - but don't say I didn't warn you.)
What is it?It's when the blood settles in the lower part of the body, causing a purplish red discoloration of the skin. The heart is no longer agitating the blood, heavy red blood cells sink through the serum by action of gravity. It can also be used by forensic investigators to determine whether or not a body has been moved (for instance, if the body is found lying face down but the pooling is present on the deceased’s back, investigators can determine that the body was originally positioned face up).
Where does it not occur?This discoloration does not occur in the areas of the body that are in contact with the ground or another object, as the capillaries are compressed.
When does it occur?Livor mortis starts 20 minutes to 3 hours after death and is congealed in the capillaries in 4 to 5 hours. Maximum lividity occurs within 6-12 hours. The blood pools into the interstitial tissues of the body. Only up to the first six hours of death can lividity be altered by moving the body. After the six hour mark lividity is fixed as blood vessels begin to break down within the body.
What can affect lividity?Exceptions to these aforementioned colors can be important forensic clues to the cause of death.
- For example, in carbon monoxide poisoning, lividity can be cherry red in color.
- When a compound called methaemoglobin forms in the blood, as occurs in exposure to lethal concentrations of potassium chlorate, nitrates, and aniline, lividity tends to be a dark, chocolate-like brown color.
- Death due to intense cold (hypothermia) or the refrigeration of a recently deceased body will produce a bright pink lividity. The latter color can also be produced if the area of the body was covered by wet clothing.
Sources: About Autopsy (picture of dead body)
Wikipedia (Picture of cadaver)
Explore Forensics (UK)
World of Forensic Science