When a human dies, they go through several distinct stages. In order: pale, cold, stiff, mottled, putrefied, decomposed, skeletonized.
What happens to a body when it stops breathing, the heart stops beating, and the brain stops thinking? A content warning for today’s post: it’s going to get icky.
First, the skin lightens. The capillaries stop getting blood so skin loses its ruddy tint; dark skin also pales, but it’s much less noticeable. This is called pallor mortis, the paleness of death.
Second, the body temperature drops. With no physical activity being driven by the heart, the dead body’s temperature decreases until it matches its surroundings. Typically this drop is about 2 degrees Celsius in the first hour and then 1 degree each subsequent hour. This is algor mortis, the coldness of death.
Third, the whole body stiffens up. This is the result of chemical changes – the bodily processes that relax muscles stop working and this causes the muscles to contract. This is rigor mortis, the stiffness of death.
Fourth, blood settles in the lower regions of the body. Obviously, it’s not being pumped around any more so it just sinks to the bottom of the corpse. This makes the upper portions even more pale and creates a purpled mottled pattern in the lower regions. (This, by the way, is one of the ways that forensic pathologists can work out if a body has been moved – the mottling appears somewhere other than the lower part of the body.) This is livor mortis, the blue blush of death.
Fifth, the body putrefies. As I mentioned in an earlier post about an ancient brain, our gut bacteria begins to eat us. The stomach and intestines are first to go, then the liver, brain, heart, lungs, and kidneys. This is the stinky phase. No more Latin names at this stage.
Sixth, the body decomposes. There are several sub-stages here, including bloat (build-up of gases from all that bacteria), “active decay” (think maggots and loss of fluids), and “advanced decay.”
Finally, all that’s left is a skeleton. This will either decay away in a couple of decades, stick around for a few hundred years, or turn into a fossil – depending on where that skeleton is placed.