How Long Does It Take for a Body to Decompose?

How long does it take for a body to decompose? The exact time differs. When a person’s heart stops pumping blood to the body, the cells and tissues are denied oxygen and rapidly start dying. Substantial decomposition mostly occurs in the course of two weeks, and the body’s soft tissues start disintegrating even with preservation. If the body does not get enough protection from the elements, it can even skeletonize in a space of a year. However, the teeth and bones can last even for a hundred years if the soil is not highly acidic and warm. The following table shows body decomposition after death in a timeline (in moderate temperature).

Air decomposition takes place two times as fast as it would under water, and four times faster as it would underground. A body’s intestines are filled with micro-organisms in their millions, and these do not die even after the person dies. These micro-organisms start to break down the dead intestine cells. Others like the bacteria known as coliforms and clostridia start invading other body parts.

At the same time, the dead body starts its intrinsic breakdown caused by the chemicals and enzymes that are being released by dead cells. For example, the pancreas is filled with digestive enzymes so it will rapidly self-digest. When tissues decompose, they release gas and green substances, and this is what makes the skin turn blue/green and have blisters. This usually starts from the abdomen. The body’s front starts to swell, the tongue protrudes, and fluid coming from the lungs starts oozing from the nostrils and mouth.

On top of all this, there is a terrible smell that comes from the release of gases like methane, hydrogen sulphide (which has a rotten egg smell) and some traces of mercaptans. This decomposition stage is reached in six days in temperate countries. It is reached much faster in tropics, but much slower in dry or cold conditions. 

Fresh

This stage immediately starts when the heart stops beating. Since there is no blood pumping round the body, the blood in the body at that time is drained to the dependent body portions under gravity, and this creates livor mortis. Livor mortis is a bluish-purple discoloration. Within 3– 6 hours after death, the body’s muscular tissues become rigid and are unable to relax, and this is known as rigor mortis. From the time of death, the body starts losing heat to the surrounding, and this is results in a cooling of the body known as algor mortis.

During the fresh stage, visible decomposition signs are limited, although there may be some blisters on the skin’s surface caused by autolysis. Autolysis is the release of cellular enzymes that initiate breakdown of tissues and cells. This is brought about by a decrease in chemical changes and pH which causes loss of structural integrity in cells.

The little oxygen left in the body is quickly depleted by aerobic microbes and cellular metabolism naturally present in the gastrointestinal and respiratory tracts. This, in turn, creates the perfect conditions for anaerobic organism proliferation. These multiply and consume the ammonia, hydrogen sulfide and carbohydrates present in the body. After the proliferation of microbial, is the second decomposition stage which is called bloat.

Bloat

This is the stage where the body shows visible signs of decomposition. In bloat stage, anaerobic metabolism takes place, and this leads to accumulation of different gases like methane, carbon dioxide and hydrogen sulfide. This accumulation of gases in the body’s cavity causes abdominal distention giving the cadaver (corpse) the bloated appearance. The integrity loss and pressure buildup from the gases may even cause rupture of the body.

If there is access of insects to the dead body, their maggots hatch and start feeding on the tissues of the body. This in turn causes hair to detach from the skin and skip to slip. The combination of gas accumulation and maggots feeding leads to skin ruptures that act as passages for the fluids and gases to the outside environment. The skin ruptures also allow oxygen access into the body, and this creates a conducive environment for aerobic microorganisms and fly larvae. This purge of fluids and gas result to the strong decaying odor.

Active Decay

This is the stage where there is great loss of mass. The loss of a dead body’s mass comes about as a result of maggot feeding and decomposition fluid purging to the surrounding environment. The fluids that have been purged accumulate around the body resulting in a CDI (Cadaver Decomposition Island). Tissues disintegration and liquefaction is now apparent in this stage, and the strong odors still persist. The end of this stage is characterized by the migration of maggots to the pupate from the body.

Advanced Decay

During this stage, decomposition is highly inhibited because there is no cadaveric material. In this stage, there is also reduced insect activity. When a carcass is on the soil, you will notice that the surrounding vegetation also dies. 

Remains/ Dry

During this stage, you may notice plant growth resurgence around the CDI. This is a sign that the nutrients in the surrounding soil are yet to resume to their normal levels. All that is now left of the cadaver is just dry skin, bones and cartilage. These will also become bleached and dry if they are exposed to the elements. If the cadaver has no tissue, it is said to have been completely skeletonized. However, if only parts of bones are exposed, it is said to be partially skeletonized.

Decaying depends on the water’s temperatures. If the water is cold, the bacteria that cause bloating may work slowly such that the body may stay on the seabed. The skin peels away from underlying tissues after absorbing water in about a week’s time. Then sea lice, crabs and fish will nibble at the flesh. Cold water also causes Adipocere formation. Adipocere is a soapy, waxy substance that is formed from the body fat that partly protects a body from decomposition. There have been bodies that have been retrieved almost completely intact when in waters under 7 degrees Celsius after some weeks. However, after about 5 years, they were retrieved as a recognizable skeleton.

In waters like the Arabian Sea (tropical waters), the story is different. Even a heavy weighted body floats to the surface after 3 or 4 days, and it is exposed to the sea birds and buffets from the sea waves. Scavenging and putrefaction creatures dismember the corpse in one or two weeks, and this eventually sinks the bones. The bones may be further broken down after some months, or years depending on the water’s acidity or be buried by marine silts.