The belief that your heart momentarily stops when you sneeze is a common misconception. While a sneeze involves significant bodily processes, it does not cause your heart to cease beating. This natural reflex is a powerful protective mechanism, not a life-threatening event.
The Science Behind a Sneeze
A sneeze is an involuntary reflex designed to expel irritants from the nasal passages. This process begins when sensory nerve endings in the nasal lining detect foreign particles like dust, pollen, or pathogens. These nerve cells transmit a signal to the brainstem, initiating the reflex.
The brain coordinates events involving multiple muscle groups. You take a deep breath, followed by the closing of your eyes and throat muscles. Pressure builds in your chest and diaphragm. Finally, the vocal cords open, and a powerful burst of air is expelled through both the nose and mouth, often at speeds up to 100 miles per hour, effectively clearing the irritant.
Sneezing and Your Heart: Dispelling the Myth
The sensation that your heart skips a beat during a sneeze contributes to the myth that it temporarily stops. However, the heart’s electrical activity remains unaffected. A momentary change in intrathoracic pressure within your chest occurs.
When you inhale deeply before a sneeze, chest pressure increases, temporarily reducing blood flow back to the heart. As you forcefully exhale, this pressure rapidly decreases, and blood flow quickly returns. These sudden pressure shifts can cause the heart to briefly alter its rhythm or delay a beat for a second or two as it adjusts. The vagus nerve, which influences both sneezing and heart rate, also plays a role. This brief alteration does not pose a threat to health.
Potential Risks and Precautions
While sneezing does not lead to death, its force can, in rare instances, result in minor physical injuries. Intense muscular contractions can cause muscle strain in the chest or back. The sudden pressure can also lead to the bursting of tiny blood vessels in the eyes, appearing as a red spot. This condition, known as a subconjunctival hemorrhage, is typically harmless and resolves on its own.
More serious, though infrequent, injuries include rib fractures, particularly in individuals with weakened bones like those with osteoporosis. The forceful expulsion of air can exert enough stress to cause a break. To minimize risks, allow sneezes to occur naturally rather than suppressing them, as holding a sneeze can increase internal pressure. Sneezing into a tissue or the crook of your arm also helps prevent the spread of droplets.