A sneeze (sternutation) is a powerful, rapid reflex designed to forcefully clear the nasal passages of irritants, such as dust, allergens, or pathogens. This involuntary, explosive event has led to speculation regarding its potential for serious physical harm. While the idea of a sneeze causing death is often considered an urban legend, the intense physiological forces involved warrant an examination of what a forceful sneeze can do to the human body.
The Mechanics of a Sneeze
Sneezing is an involuntary reflex initiated when irritants stimulate the nasal mucosa, sending a signal via the trigeminal nerve to the brainstem’s “sneeze center.” This center coordinates muscular contractions in the chest, abdomen, and throat. Before expulsion, the glottis briefly closes, allowing a rapid buildup of intrathoracic pressure within the lungs.
The motor phase is the sudden, forceful release of this compressed air, the audible “achoo.” Expelled air has been measured to reach speeds of 10 to 35 miles per hour. This rapid expulsion effectively clears the nasal cavity, requiring powerful contractions of the chest and abdominal muscles.
Documented Non-Lethal Injuries
Although sneezing is natural, the violent muscular contractions and pressure changes can cause non-lethal physical injuries. A common issue is musculoskeletal strain, particularly in the core, due to the sudden, intense flex of the abdominal and intercostal muscles. Individuals with pre-existing conditions, such as osteoporosis or weakened bones, have experienced rib fractures from a forceful sneeze.
Less frequently, the pressure surge can damage soft tissues. Cases of pneumomediastinum have been reported, where air escapes from the lungs into the mediastinum (the central chest compartment). The pressure can also affect the eyes, occasionally rupturing small blood vessels in the conjunctiva, resulting in harmless, temporary red spots.
Addressing the Lethal Myth
For a healthy individual, the answer to whether a sneeze can cause death is definitively no. The human body is engineered to withstand the pressures generated by a natural sneeze. The myth of death from sneezing focuses on rare, pre-existing conditions like cerebral and aortic aneurysms.
A sneeze causes a momentary spike in intrathoracic and blood pressure, similar to a forceful cough. Healthy blood vessels typically tolerate this transient increase. However, if a person has an already fragile, ballooned blood vessel (aneurysm), the sudden pressure surge could theoretically trigger a rupture.
In this scenario, the sneeze is not the fundamental cause of death, but the final trigger aggravating a severe underlying vascular weakness. This fragile aneurysm is likely to rupture spontaneously or from other common activities. Therefore, while a sneeze might precede a fatal rupture in a patient with an undiagnosed condition, a healthy person cannot generate enough force to cause their own death.
The Dangers of Suppressing a Sneeze
Paradoxically, suppressing a sneeze poses a far greater risk of injury than allowing it to proceed naturally. When a person pinches their nose and closes their mouth, the immense pressure meant to be vented outward is trapped and redirected internally. Studies show this maneuver can increase respiratory system pressure by five to 24 times the normal expulsive force. This concentrated pressure can force air into vulnerable cavities, leading to serious complications.
Common Injuries from Suppression
One of the most common injuries is a ruptured tympanic membrane (eardrum), as pressure travels up the Eustachian tubes into the middle ear. More severe, though rare, cases involve barotrauma to the pharynx, resulting in a tear in the soft tissues at the back of the throat. This can lead to severe pain, swelling, and difficulty swallowing. The safest course of action is to allow the sneeze to occur naturally, preferably into a tissue or the crook of an elbow.