In the first few hours after death, several changes begin to occur in the body.
- Livor Mortis: When the heart stops beating, blood begins to pool in the lower parts of the body due to gravity. This discolouration of the skin, known as livor mortis, typically sets in within 30 minutes to 2 hours after death.
- Algor Mortis: The body begins to cool down, losing about 1-2 degrees Celsius every hour until it reaches the ambient room temperature. Cooling first occurs in the extremities, such as the hands and feet, and then progresses to the torso.
- Rigor Mortis: As a result of chemical changes in the muscles, they begin to stiffen and contract. Rigor Mortis starts in the jaws, neck, and spreads to the rest of the body within a few hours. At its peak, which is usually 24 hours after death, Rigor Mortis prevents the limbs from being moved.
Postmortem Changes
Further decomposition process begins a few hours after death:
- Autolysis: This is the breakdown of tissues due to the body's own enzymes. Initially, the internal organs are affected, followed by the muscles and other tissues.
- Bloating: As bacteria in the gut start multiplying, they produce gases that cause the body to swell and bloat.
- Discolouration: The skin changes colour as the haemoglobin in the blood breaks down. Greenish discolouration often appears on the skin during this process.
- Liquefaction: As autolysis continues, tissues become liquefied, resulting in the breakdown of the internal organs.
- Putrefaction: Beyond the liquefaction stage, putrefying bacteria release foul-smelling gases that speed up the decomposition process.
Advanced Decomposition
Months to years after death, the body undergoes advanced stages of decay:
- Desiccation: If the environment is dry, the body undergoes desiccation, where it becomes leathery and hard.
- Mummification: In conditions where little water and air are present, the skin and internal organs can become dry and paper-like, preserving the body for an extended period.
- Adipocere Formation: In moist conditions with limited air circulation, the body's fat transforms into a waxy white substance called adipocere, which can delay decomposition.
Eventually, the body will completely decompose, leaving only the bones, which can persist for centuries or longer under certain conditions.