Fluid resembling blood leaking from the mouth of a deceased person is often unsettling, but it is frequently a discolored discharge resulting from natural postmortem changes, not fresh bleeding. This phenomenon is primarily explained by pressure changes inside the body, the effects of gravity, and the body’s transition into decomposition. Understanding these processes clarifies why fluids are sometimes expelled from the oral and nasal passages after circulation has ceased.
Postmortem Fluid Expulsion
The most frequent cause of reddish-brown fluid expulsion is postmortem purging, which is linked to the onset of decomposition. This process involves the internal production of gases that build up pressure within the body’s cavities. Putrefaction, the breakdown of tissues by bacteria, begins shortly after death, driven primarily by the body’s own intestinal flora.
As bacteria consume tissue, they generate gases like hydrogen sulfide, methane, and carbon dioxide within the gastrointestinal tract. This gas formation causes the abdomen to distend and creates significant internal pressure, forcing fluids out through the mouth and nostrils. Purge fluid is a mixture of decomposed stomach contents, partially digested blood components, and fluids from the lungs or other organs.
Purge fluid typically presents as a foul-smelling, dark red or reddish-brown discharge, often mistaken for massive bleeding. The reddish hue comes from the breakdown of hemoglobin within red blood cells, which mixes with gastric or pulmonary fluids. The substantial internal pressure pushes this fluid up the esophagus from the stomach or out of the trachea from the lungs. This expulsion is a sign of advancing decomposition.
Bleeding Caused by Internal Pathology
In some circumstances, the expelled fluid is true blood that collected internally before or at the time of death, rather than active postmortem bleeding. Severe underlying medical conditions can lead to massive internal hemorrhage, causing blood to pool in the airways or digestive tract. For example, liver disease can cause large, fragile esophageal varices that rupture just before or during death.
If a massive gastrointestinal hemorrhage occurs, a large volume of blood is released into the stomach and esophagus, but the body’s protective reflexes, like vomiting, may cease before all the blood is cleared. After death, this pooled blood can then be passively expelled from the mouth due to gravity or due to minor internal pressure changes. Similarly, severe pulmonary edema, often associated with heart failure, causes fluid to build up in the lungs.
This fluid, sometimes mixed with blood, produces a characteristic light-pink, frothy discharge expelled from the mouth and nose. The blood component is a small amount mixed into the lung fluid, resulting from the failure of small capillaries. While the heart is no longer pumping, the cessation of circulation allows blood to pool in the dependent areas of the lungs, and slight pressure can push the accumulated fluid out.
Trauma Related to External Intervention
Bleeding from the mouth can also result from physical interaction with the body that occurs around the time of death, particularly if medical interventions were attempted. Cardiopulmonary Resuscitation (CPR) requires applying significant force to the chest, which can lead to internal injuries. In one study, nearly 94% of autopsies with a history of recent CPR showed related injuries.
Chest compressions, which require a force of about 100 to 125 pounds, frequently fracture the ribs and sternum. These broken bones can lacerate underlying soft tissues, including the lungs or major blood vessels, causing internal bleeding into the chest cavity. This blood may then enter the airways and exit through the mouth or nose.
Procedures like intubation—inserting a tube into the trachea—can cause minor trauma to the mucosal lining of the mouth, throat, or larynx, leading to some bleeding. Physical trauma to the face or head that occurs during the event leading to death, or accidental impact during the handling or movement of the body, can also result in blood leaking from the oral cavity. These causes are considered iatrogenic, meaning they are a direct result of medical or external intervention.