Why Do Human Remains Develop an Odor?

Upon death, a human body nearly immediately begins the process of decomposing or breaking down. While this biological reality is unpleasant, understanding the essential elements of this process is helpful. This includes having a basic appreciation of why a body begins to smell in the aftermath of a death.

The Biological Processes After Death

When a person’s life ends, the focus naturally is on the sad reality that major bodily functions have ended. The heart stops beating, the lungs stop bringing oxygen into the body, the brain stops working. Despite the cessation of major bodily functions, bacteria contained inside major organs continues to live. This includes bacteria naturally present in a deceased individual’s pancreas and intestines.

When a person dies, bacteria naturally begins to attack the body itself, beginning the process of breaking down that body. When the blood flow stops at the time of death, bacteria lose their primary source of nutrients and must seek them elsewhere.

The pancreas provides a sharp illustration of what bacteria do after a person dies. The bacteria feed on the pancreas, resulting in the organ essentially digesting itself. The same occurs in the intestines, although not quite in as a dramatic fashion.

When the bacteria completes its work on the pancreas and intestines, these organs completely breakdown, releasing the bacteria to travel throughout the body and begin attacking other organs. This process results in the accumulation of an incredible amount of noxious smelling gas within the body.

As the gas starts to accumulate, it causes the body itself to start to change colors from its natural hue to green, then purple, and ultimately to black. At the same time, some of the noxious, foul-smelling gas escapes from the decomposing body.

The amount of gas involved cannot be underestimated. Despite a good deal of gas escaping from a decomposing body, the pressure remains so great internally that the possibility of a deceased body ultimately exploding exists.

Gases and Chemical Compounds and the Odors of Death

At the heart of the decomposition process, which results in the potential for the odor to be associated with the remains of a deceased person, is chemistry. When a person dies, the remains begin the process of releasing various gases as well as approximately 30 different chemical compounds. Some, but not all, of these gases and compounds possess recognizable and even highly unpleasant odors.

The six most pervasive odors associated with a decomposing human body include:

  • Cadaverine and putrescine (rotting fish odor)
  • Skatole (feces odor)
  • Indole (mothball-like odor)
  • Hydrogen sulfide (rotten egg odor)
  • Methanethiol (rotting cabbage odor)
  • Dimethyl disulfide and trisulfide (foul garlic odor)

The reality is that as a human body decomposes, all of these various unpleasant odors can arise simultaneously. The resulting combination can prove to be overpowering and persistent.

If a body is left unattended for more than a few days after death, the foul odors associated with decomposition can permeate the room in which the remains remained. Because of the strength of these odors, professional remediation oftentimes is required in order to eliminate them.

Preserving the Body After Death to Significantly Arrest the Decomposition Process

Funeral and burial customs in the United States, and other countries around the world, oftentimes necessitate the embalming of a body after death. This is done to maintain the remains of a deceased person for presence at a funeral at some point in time after death. In addition, the laws of different states, including California, require embalming in certain circumstances.

The standard embalming process used in the United States usually does not completely arrest the decomposition process. However, embalming does forestall the decomposition process for some time.

Ideally, the embalming process occurs within a day after death. The sooner this occurs, the more effective it is at staving off decomposition. In addition, immediately placing a body in cold storage after death and before embalming is a technique that also brings the decomposition process to a virtual stop. When brought to a virtual stop, the foul odors associated with decomposition are eliminated, at least for a more extended period.