# Postmortem Decomposition

> Decomposition in MBBS Forensic Medicine — putrefaction stages, adipocere, mummification, Casper dictum and factors modifying decay.

- Canonical URL: https://prepelephant.com/topics/mbbs/forensic-medicine/postmortem-decomposition
- Exam / course: MBBS · Subject: Forensic Medicine
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-02
- Last updated: 2026-10-02
- How to cite: "Postmortem Decomposition", PrepElephant, https://prepelephant.com/topics/mbbs/forensic-medicine/postmortem-decomposition

## Direct answer

Postmortem decomposition is the natural dissolution of the body after death in three principal forms — putrefaction, adipocere formation and mummification — depending on the environment. Putrefaction, the usual process in India, is bacterial and enzymatic destruction: greenish discolouration of the right iliac fossa within about twelve to eighteen hours in warm weather, then gas formation, bloating, marbling, skin slippage and finally skeletonisation over weeks to years. Adipocere and mummification are modifications of decay in wet-airless and dry-airy environments, and both can preserve features and injuries for long periods.

## What you must remember

- **First external sign:** greenish discolouration over the caecum in the right iliac fossa within roughly twelve to eighteen hours in the Indian climate, spreading over the abdomen and body.
- **Sequence in the first days:** marbling of veins by twenty-four to thirty-six hours, gas with bloating of face, abdomen and scrotum, froth at mouth and nose, skin blisters and slippage, hair and nails loosening, and purging of fluids.
- **Internal order:** larynx and trachea first, then stomach, intestines, spleen, liver and brain; the uterus in females and prostate in males resist longest.
- **Casper's dictum:** one week in air equals about two weeks in water and eight weeks in soil for the same degree of decomposition.
- **Adipocere:** grey-white, firm, waxy material from hydrolysis and hydrogenation of fats, beginning from about three weeks in warm Indian conditions, best formed in moist, warm, airless environments such as submerged or clay-buried bodies.
- **Mummification:** dehydration and shrinkage into a leathery, brownish, shrivelled body in dry, moving air, preserving features, wounds and identity for months to years.
- **Modifying factors:** heat, humidity, sepsis before death, drowning and open wounds hasten putrefaction; cold, dry air, wasting and deep burial in absorbing soil delay it.

## Common confusion

Adipocere is confused with ordinary decomposed fat, and mummification with simple drying — adipocere is a chemical conversion that resists further decay, while putrefaction liquefies tissue. A second trap is reading gas splits in the skin as wounds; postmortem heat ruptures and putrefactive splits have no vital reaction, unlike true injuries.

## Exam-focused takeaway

Examiners ask the first sign of putrefaction with its timing, the Casper's dictum ratios, the conditions and timeline for adipocere, the order of internal organ decay, and the organ that resists longest. MCQs test the modifying factors — sepsis, drowning and humidity hasten, cold and dryness delay. In viva, explain how you would look for injuries in a decomposed body and why the uterus persisting helps identify a female body.

## Frequently asked questions

### What is the first external sign of putrefaction?

Greenish discolouration over the right iliac fossa over the caecum, within about twelve to eighteen hours in warm Indian conditions.

### What is Casper's dictum?

Decomposition proceeds roughly eight times faster in air than in soil and twice as fast in water as in soil — one week in air equals two in water and eight in earth.

### How does adipocere form?

Fats hydrolyse to fatty acids that combine with calcium and magnesium soaps in moist, warm, airless surroundings, forming firm waxy material from about three weeks onward in India.

### Which organs putrefy first and last?

The larynx and trachea first, then the stomach and intestines; the uterus in females and the prostate in males resist longest.

### Why can putrefaction destroy medico-legal evidence?

Gas bloating distorts features and injuries, hair and nails loosen, tissues liquefy and wounds lose vital reaction, making the cause of death and identity progressively harder to establish.

### What is mummification and when is it seen?

Shrivelling and hardening of the body in dry, warm, ventilated environments, which desiccates the tissues and preserves features and injuries for months to years.