Stuff You Should Know – "How Sneezing Works"

Hosts: Josh Clark & Charles W. "Chuck" Bryant
Podcast: Stuff You Should Know (iHeartPodcasts)
Date: March 20, 2026

Episode Overview

This episode dives into the biology, neurology, and cultural curiosities of sneezing—why we do it, how it works, and all the weird, gross, and fascinating facts surrounding this ancient reflex. Hosts Josh and Chuck pepper their conversation with jokes, personal anecdotes, and some truly memorable cultural rabbit holes.

Key Discussion Points

The Biology & Mechanics of Sneezing

• Sternutation:

  • The technical term for sneezing is "sternutation," an old, rarely-used word (03:19).

    "If you're a scientist and you want to be a real stiff, you probably say sternutation. If you're a scientist that wants to be friends with people, you'll still probably say sneezing." — Chuck (03:38)

• Why We Sneeze:

  • Sneezing is an involuntary reflex mainly designed to eject unwanted particles from the nose. It’s an ancient and efficient system shared by many animals (05:09).

• Nasal Filtration System:

  • The nose is an impressive filtration system—narrow passages create turbulence, sending inhaled particles to the mucosal lining and then down the throat most of the time. When this system is overwhelmed, the sneeze reflex kicks in (06:43).

• How a Sneeze Works:

  • Afferent phase: Irritation (from things like pollen or dust) triggers nerves in the nasal mucosa, sending a signal to the "sneeze center" in the lateral medulla of the brain (09:25).
  • Efferent phase: The sneeze center returns the signal, activating facial and chest muscles to produce a powerful expulsion—air can reach speeds up to 100mph (12:22).

• Muscle Involvement:

  • Sneezing involves many body parts: diaphragm, abdomen, chest, vocal cords, even facial muscles (11:12).

• Myth Busting:

  • "You can’t pop your eyes out if you sneeze with them open" (13:13).
  • Sneezing is involuntary: You can’t really make yourself sneeze at will, but you can try to induce one with certain triggers (13:33).

The Neuroscience of Sneezing

• Sneeze Center Location:
  • For years, scientists suspected the lateral medulla controlled sneezing. Decisive proof came from a fisherman who stopped sneezing after a lesion in that region—capsaicin (chili pepper) in his nose would burn, but not trigger sneezing (19:09).

  • “They found this lesion on his lateral medulla, and they said, sneezing center. Welcome to our understanding.” — Josh (20:43)

Types and Triggers of Sneezing

• Types of Rhinitis:

  • Allergic, occupational (like flour dust), hormonal (pregnancy, puberty), drug-induced (NSAIDs, mushrooms), and geriatric (elderly with atrophied glands) (22:18, 24:26).

• Photic Sneeze Reflex ("ACHOO" syndrome):

  • About 23–25% of people sneeze in response to sunlight (photic sneezing). Genetically inherited, this is known as Autosomal Dominant Compelling Helio-Ophthalmic Outburst (ACHOO) syndrome (25:15, 27:24).

  • “I am a photic sneezer more than I'm a native born Toledoan even. Maybe they're tied.” — Josh (25:31)

  • Typical sneeze patterns (single, double, triple) can also be hereditary (26:40).

• Rare & Fascinating Triggers:

  • Sexual ideation/orgasm: Some people sneeze when aroused or after orgasm; about 20 reported to a researcher via online forums (33:46).
  • Full stomach ("seneciation"): Only four families are documented with this rare reflex where overeating triggers sneezing (30:07).
  • Nose hair plucking: Can cause sneezing or watery eyes due to facial nerve connections (32:05).

• Intractable (psychogenic) sneezing:

  • Mostly adolescent girls; some reported hundreds of sneezes a day for months or years.
  • Donna Griffiths sneezed for 977 days straight, averaging 1,000,000 sneezes in the first year (35:38).

Sneezing, Contagion, and Public Health

• Expulsion Force and Distance:

  • Slow-motion studies show sneezes can eject particles up to 25–27 feet, with finer aerosols lingering in the air for minutes, or even longer in rare lab conditions (41:22).

  • “If you would take a bucket of paint and just throw the paint out of the can into the air, sort of is how a sneeze works.” — Chuck (41:46)

• How it Spreads Germs:

  • Airflow in the room, turbulence, and aerosols mean sneezes can go much farther than a simple cough (43:24).
  • Best hygiene: sneeze into tissues or your elbow, wash your hands (43:32).

• COVID Context:

  • Outdoors, risk from sneezed particles is much lower compared to indoors due to quick dispersion (45:59).

Sneezing in Culture & Folklore

• "Bless you" and Global Variants:

  • Origin in the Black Plague: Pope Gregory VII may have encouraged “God bless you” to protect people believed to be in mortal danger (47:08).
  • Earlier Christians were told to ignore sneezes entirely (47:42).
  • Many languages use blessings or good luck phrases; the Greeks said, “May Zeus preserve you” (48:45).

• Other Beliefs:

  • In China/Japan, sneezing means someone is talking about you (50:50).
  • Folktales: sneezing means your soul escapes or a demon invades—Zoroastrians saw sneezing as victory over evil (49:51).
  • Urban legends debunked:
    • Your eyes won’t pop out if you keep them open while sneezing (51:13).
    • Your heart does not stop when you sneeze (52:00).
    • Sneezing after sex does not prevent pregnancy (52:38).
    • Suppressing sneezes can be dangerous—one man ruptured his throat trying (53:09).

    • “The pressure was so great, it broke open his throat.” — Josh (53:20)

• Micro-Affections:

  • Saying “bless you” to strangers is a “micro affection,” a tiny moment of kindness promoted in many cultures (49:06).

Notable Quotes and Moments

• On the elegance of sneezing:

  “It’s just a very efficient system that the human body has worked out…to allow your nose and your brain to act as bouncers and just say, get out of my body fast. You’re cut off, pal.” — Chuck (04:33)

• On the world’s longest sneezing fit:

  “A million sneezes in the first 365 days…a sneeze a minute over 24 hours, compressed into, say, 10 or 12 hours that she was awake that day.” — Josh (36:00)

• On sneeze hygiene during the pandemic:

  “But yeah, the ideal is to sneeze into a tissue, throw your tissue away and wash your hands thoroughly. That’s what you’re supposed to do after you sneeze. Every time. Every single time.” — Josh (44:07)

• On “bless you” as a micro-affection:

  “It’s almost like an involuntary micro affection, I think for most, you know, non-monsters for sure.” — Chuck (49:06)

Timestamps for Major Segments

• 03:19 – Introduction of "sternutation" and efficient nose filtration
• 09:25 – Neural phases and sneeze reflex explained
• 12:22 – Muscle groups involved; how forceful a sneeze can be
• 13:13 – Mythbusting: Can you keep your eyes open while sneezing?
• 19:09 – The sneeze center, neuroscience, and the "fisherman case"
• 22:18 – Triggers: rhinitis, allergens, occupational/hormonal factors
• 25:15 – Photic sneeze reflex, genetics & “ACHOO” syndrome
• 30:07 – Rare sneezing triggers: full stomach, arousal, etc.
• 35:38 – Psychogenic/intractable sneezing and record holders
• 41:22 – Droplet speed, distance, and slow-motion research
• 43:32 – Proper sneeze hygiene & public health
• 47:08 – “Bless you!” across world cultures, origins, and micro-affection
• 49:51 – Folklore: demons, souls, Persian & other cultural beliefs
• 51:13, 52:00 – Urban legends: eyes popping, heart stopping
• 53:09 – Danger of stifling sneezes

Memorable Moments

• Josh and Chuck’s lighthearted banter about the weirdness of sneezing, especially in pandemic times, and astonishment that they’d never covered sneezing in over a decade of SYK ("felt like a first ten" episode).
• Joking about “sneeze patterns” as an inherited trait: “Double sneezers beget double sneezers.” — Chuck (26:44)
• Vivid description of how particles travel during a sneeze, likened to throwing a bucket of paint (41:46).
• Chuck’s riffing on old and modern “bless you” rituals, and their aspiration to bring back “May Zeus preserve you” as a new/old sneeze reply (48:45).

Conclusion

“Stuff You Should Know” delivers a surprisingly fascinating exposé on the humble sneeze—spanning biology, genetics, public health, and superstition—wrapped in the show’s signature humor and curiosity. If you’re a regular sneezer or just a sneezing fan, you’ll never see a “Bless you!” the same way again.

For questions, feedback, or to share your favorite sneeze-related urban legend, email stuffpodcast@iheartradio.com.