How Sneezing Works - Stuff You Should Know Recap

Podcast: Stuff You Should Know

Published: 2026-03-20

What Happened

Sneezing, or sternutation, is a fascinating and complex reflex that serves as the body's defense mechanism against irritants in the nasal passages. The process involves a coordinated response between the lateral medulla in the brain and the olfactory, ethmoidal, and trigeminal nerves. When particles irritate the nasal mucosa, histamines are released, triggering a powerful expulsion of air that can reach speeds up to 100 miles per hour.

Iguanas hold the record for sneezing frequency in the animal kingdom, using it as a natural part of their digestive process. Meanwhile, dogs experience a related phenomenon known as reverse sneezing, which is not a true sneeze but is associated with their nasal passages. Interestingly, sneezing is an involuntary reaction, and despite myths, your heart does not stop when you sneeze.

The episode delves into unique triggers of sneezing, such as photic sneezing, which affects 23% of people and is caused by exposure to bright light. This reflex is inherited in an autosomal dominant pattern. There are also rare cases like snatiation, where sneezing occurs after eating too much, and instances where individuals sneeze due to sexual arousal or post-orgasm.

Historically, sneezing has held various cultural significances. During the Black Plague, Pope Gregory VII recommended saying 'God bless you' to a sneeze, whereas in China and Japan, it is thought that sneezing indicates someone is talking about you. In Persia, sneezing was seen as a victory over a demon, highlighting how interpretations vary across cultures.

Occupational rhinitis is another sneezing trigger, caused by exposure to irritants such as cleaning supplies or flour in workplaces. Hormonal changes, certain medications, and even aging can lead to various forms of rhinitis, emphasizing how diverse the causes of sneezing can be.

The episode also touches upon some sneezing-related myths and facts. For example, it's impossible to sneeze while sleeping, and stifling a sneeze can be dangerous, as demonstrated by a man in the UK who ruptured his throat attempting to do so. Sneezing into your elbow is recommended to prevent the spread of contagious germs, which can remain airborne for weeks under the right conditions.

Key Insights

• Sternutation is the scientific term for sneezing, with records dating back to 1576, and involves a complex interaction of the brain's lateral medulla and nasal nerves.
• Iguanas are the most frequent sneezers in the animal kingdom, utilizing sneezing as part of their digestive process, while dogs exhibit reverse sneezing related to nasal passages.
• Photic sneezing affects 23% of the population and is triggered by bright light. It follows an autosomal dominant inheritance pattern, making it a unique genetic trait.
• Cultural interpretations of sneezing vary widely, from being a signal of someone speaking about you in China and Japan to a protective blessing during the Black Plague as suggested by Pope Gregory VII.