Suppressing a sneeze is a common, reflexive action, usually driven by politeness or a desire to prevent the spread of germs. This act typically involves pinching the nostrils shut and simultaneously clamping the mouth closed. While stifling this bodily function is understandable, this simple maneuver dramatically alters the body’s mechanics. Understanding what happens when this powerful biological event is contained is important for recognizing the potential risks of trying to stop the sneeze.
The Mechanics of a Sneeze
A sneeze, medically termed sternutation, is an involuntary, protective reflex designed to forcefully expel foreign irritants from the nasal passages. This reflex arc begins when sensory receptors in the nasal lining detect an irritant, sending a signal along the trigeminal nerve to the brain’s specialized sneeze center. The body responds by coordinating a complex series of muscular contractions involving the chest, diaphragm, and throat. The process involves a deep breath, followed by the buildup of immense pressure behind the closed vocal cords. When the cords open, air, mucus, and particles are explosively ejected from the nose and mouth, often reaching speeds up to 100 miles per hour.
Pressure Dynamics of Containment
Closing the nose and mouth during the expulsion phase prevents the generated pressure from escaping through its intended airways. The force, produced by the diaphragm and chest muscles, is contained within the upper respiratory tract. This redirection causes the internal pressure to escalate, potentially becoming 5 to 20 times higher than if the sneeze were allowed to exit naturally. The heightened pressure seeks the path of least resistance, forcing compressed air backward and laterally into adjoining cavities. These cavities include the delicate structures of the sinuses, the ocular orbits, and the narrow Eustachian tubes that connect the back of the throat to the middle ear.
Documented Health Risks of Suppressing a Sneeze
The redirection of this immense internal force can lead to specific physical injuries across several areas of the head and neck. A common consequence involves the ears, where pressure forced through the Eustachian tubes can rupture the thin tympanic membrane, or eardrum. This perforated eardrum can result in pain, temporary hearing loss, and may require medical intervention to heal properly.
More seriously, the sudden spike in pressure can cause barotrauma, leading to subcutaneous emphysema, where air is forced into the soft tissues of the neck or chest. This condition causes air bubbles to crackle under the skin. In extremely rare instances, the intense pressure has been known to cause a pharyngeal rupture, tearing the tissue in the throat. This type of neck injury, where air leaks into the chest cavity (pneumomediastinum), is a serious medical event. Less common risks include the rupture of small blood vessels in the eyes, causing temporary redness, or orbital fractures due to pressure buildup in the sinus cavities adjacent to the eyes.
Recommended Sneeze Etiquette
Since suppressing a sneeze risks injury and an open sneeze spreads infectious droplets, an effective middle ground is necessary. The recommended practice is to allow the sneeze to exit, but redirect its trajectory away from others. Instead of using bare hands, sneeze into a tissue and immediately discard it. If a tissue is unavailable, the safest and most hygienic alternative is to turn your face and sneeze directly into the crook of your elbow, often called the “Dracula move.” This technique contains the expelled droplets while keeping hands clean. For those who wish to manage the initial tickle, gently pressing a finger firmly against the area just above the upper lip may interrupt the signal traveling along the trigeminal nerve, potentially preventing the sneeze from fully developing.