Postmortem bleeding from the mouth, often a distressing and misunderstood sight, is referred to by medical professionals as postmortem purging. This expulsion of fluid results from non-violent processes that begin internally once the body’s life-sustaining systems cease operation. The reddish-brown discharge often looks like blood but is usually a mix of bodily fluids expelled due to predictable physical and biological changes. These occurrences are a natural consequence of physical laws and bodily breakdown.
Gravity and Postmortem Fluid Dynamics
When the heart stops beating, blood circulation immediately ceases, removing the force that keeps blood distributed throughout the body. The passive force of gravity then takes over, initiating hypostasis, or livor mortis. This process involves the settling of blood into the capillaries and vessels of the body’s lowest, or dependent, areas.
If the head is in a lower position, blood will settle into the tissues of the head and neck. Within the circulatory system, the blood remains unclotted for a period due to the postmortem breakdown of clotting factors. This fluid is free to move and pool within the relaxed vascular network.
As blood collects in the dependent vessels, pressure within the capillaries increases. The integrity of the vascular walls diminishes rapidly after death, allowing fluid to leak into the surrounding tissues. If the mouth and nose are positioned downward, the accumulated fluid is passively forced out. This drainage is a physical process where pooled fluid, under hydrostatic pressure, follows the path of least resistance.
Internal Pressure from Decomposing Tissue
A later cause of fluid expulsion is the buildup of internal pressure from decomposition gases, which leads to the formation of purge fluid. Decomposition, or putrefaction, begins when the body’s own enteric bacteria proliferate and metabolize soft tissues. This microbial activity generates significant volumes of gas, including hydrogen sulfide, methane, and carbon dioxide.
This gas accumulation causes the abdomen and chest cavity to inflate, commonly known as bloating. The substantial pressure inside the torso physically squeezes the internal organs. This intense internal force pushes fluids from the stomach, lungs, and liquefied soft tissues upwards through the natural passages.
The resulting expelled fluid is a foul-smelling, reddish-brown liquid that can exit through the mouth and nostrils. This purge fluid is a slurry of decomposition products, residual stomach contents, and serosanguinous liquid. Its appearance typically occurs hours to days after death, depending significantly on environmental temperature, which accelerates bacterial activity.
Ante-mortem Injuries and Medical Procedures
Sometimes, the blood expelled after death originates from an injury or medical condition that occurred while the person was still alive. Conditions such as a perforated peptic ulcer, a ruptured aortic aneurysm, or severe trauma can cause substantial internal hemorrhage. The blood from these ante-mortem events accumulates within the body cavities and may be expelled postmortem by gravity or decomposition pressures.
Medical interventions performed immediately before or during the dying process can also result in bleeding that manifests after death. Cardiopulmonary Resuscitation (CPR) is an aggressive procedure that involves applying high force to the chest. This action commonly causes fractured ribs and sternums, which can lead to lacerations of the lungs, liver, or spleen and subsequent internal bleeding.
The blood from these CPR-induced internal injuries can be expelled through the mouth during resuscitation or shortly after circulation ceases. Similarly, traumatic endotracheal intubation can cause mucosal tears or pharyngeal lacerations in the upper airway. The blood from these injuries accumulates in the oral cavity, ready to drain or be forced out by handling or internal pressure.