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Sneezes and Sneezing: Causes, Facts, Myths, and Mysteries

Linda Crampton is an experienced teacher with a first-class honors degree in biology. She writes about the scientific basis of disease.

A Useful and Slightly Mysterious Behavior

Sneezing is a brief but explosive process that is very effective at moving irritating material out of the nose. The process can be sudden, surprising, embarrassing, and annoying. It can also be very inconvenient, especially when it occurs frequently. Most of us are temporarily helpless while we sneeze. Despite these problems, sneezing is an interesting phenomenon.

The medical term for sneezing is sternutation. Many different factors can stimulate sternutation, including infections and allergies, inhaled irritants, a sudden exposure to bright sunlight or a cold temperature, and a stomach that is very full of food. The process is still slightly mysterious, even for scientists. Most people no longer believe that a sneeze represents a soul leaving the body as some people in the past thought, but myths about sternutation still exist.

Humans aren't the only organisms that sneeze. Other mammals also perform the behaviour, and so do birds and some reptiles.

Why Do We Close Our Eyes When We Sneeze?

Do we close our eyes when we sneeze to stop our eyeballs from popping out due to the force that's created, as some people claim? Researchers say that this is very unlikely. In fact, some people are able to sneeze with their eyes open (although this is very difficult to do) and their eyeballs stay in place. There may be a slight increase in blood pressure behind the eyes during sternutation, but it's not enough to push the eyeballs out.

Perhaps closing our eyes prevents bacteria and fluid from entering the eyes during the sneeze? Most researchers consider this to be unlikely too, since the fluid and particles from the nose are propelled away from our bodies when we sneeze, sometimes for long distances.

The most likely explanation is that closing our eyes while sneezing is part of a strong reflex action, just as our lower leg moves involuntarily when the knee is tapped in a particular place. Some people with stress incontinence release urine when they sneeze. This is thought to be part of the reflex. It may seem unsatisfying to think that the phenomenon of closing the eyes while sneezing has no purpose, but that's the current belief of researchers.

Hygiene When Sneezing and Fighting the Flu

The Mechanics of Sternutation

The lining of the nostrils is called the nasal mucosa. When the mucosa is stimulated by an irritation, nerves in the nose send signals to the sneeze center of the brain. This centre is located in the medulla oblongata at the base of the brain. We don't control this area of the brain consciously.

During a sneeze, the medulla oblongata sends signals to the chest and throat muscles and also signals the eyes to shut. The tongue presses against the roof of the mouth. The person takes a deep breath and mucus is forcefully expelled out of the nose and saliva out of the mouth. Chest and stomach muscles contract to help the expulsion.

An average sneeze lasts between two and three seconds and can't be stopped once it has begun. Some people always sneeze more than once after they start the activity. This seems to be due to individual variations in the reflex action.

A sneeze can spread viruses and other pathogens.

A sneeze can spread viruses and other pathogens.

What Makes Us Sneeze?

The nasal mucosa may be irritated by particles that enter the nostrils from the outer or inner environment, such as dust, pollen, pet hair, pepper, or fluid. Allergies may also lead to mucosal irritation. A chemical called histamine is released from certain cells in the body during an allergic reaction. Histamine causes inflammation and swelling of the nasal mucosa. The mucosa also swells when we have a cold. A swollen mucosa is very sensitive to irritation. Additional infections that affect the respiratory tract (such as the flu) can also trigger sneezes.

In some people, the sneeze reflex can also be produced by other factors. These include overfilling the stomach or entering bright sunlight after being in a darker building. Some people sneeze when they pluck their eyebrows or when they are exposed to cold air or strong odors. Emotional arousal may trigger sneezing in certain people. Sometimes the process is related to an epileptic seizure.

Seek Help When Necessary

An occasional sneeze is probably unimportant, though it would be a good idea to cover the nose to prevent problems for other people. Anyone who sneezes frequently or over an extended period of time and who doesn't have a confirmed explanation for the behavior should visit a doctor. A medical explanation for the problem could be important.

Sternutation in Bright Sunlight

Sneezing in bright sunlight is known as a photic sneeze or the ACHOO syndrome (Autosomal-Dominant Compelling Helio-Ophthalmic Outburst Syndrome). The term was created by scientists having some fun, since the sneeze is often thought to have no effect on a person's life. However, experiencing a photic sneeze while driving a vehicle could have serious consequences if the eyes close. It's important that people who experience the sneeze wear sunglasses if they're driving on a sunny day.

The sneeze appears when susceptible people enter bright sunlight after being in relative darkness. Between 20% and 35% of the population experience photic sneezes. The phenomenon is believed to have a genetic basis.

The Eye and the Optic Nerve

An error in the transfer of information through the optic nerve seems to be the immediate basis of a photic sneeze. Information from the retina of our eyes travels along the optic nerve to the brain, which creates an image. The retina is the light-sensitive layer at the back of the eye. The optic nerve also triggers the brain to constrict the pupil in bright light to prevent the light from damaging the retina. The pupil is the round opening in the center of the iris (the colored part of the eye) that enables light to enter the eyeball.

How Does a Photic Sneeze Occur?

A nerve called the trigeminal nerve is located close to the optic nerve. The trigeminal nerve detects stimuli on the face, including the nose, and sends the information to the brain. It has several branches.

When people who experience photic sneezes enter bright sunlight, it's thought that an error is made in nerve conduction. As the optic nerve is transmitting a signal to the brain to "tell" it that the sunlight is strong and potentially irritating, some of the signal is believed to cross over into the nearby trigeminal nerve. When the brain receives the signal from the trigeminal nerve it responds as though the nose has been irritated and causes a sneeze.

A branch of the trigeminal nerve goes to the eyebrows. Plucking the eyebrows may trick the brain into thinking that the nose has been stimulated and trigger it to produce the sneeze reflex.

There may be an additional or different explanation for the photic sneeze. Some researchers noticed changes in the behavior of the brain's visual cortex in susceptible people when they were exposed to light. Only ten subjects were involved in the research, however. It's unknown how common or important the changes are.

A researcher mentioned in the last reference below says that it's hard to get funding to investigate photic sneezes because they are considered to be unimportant. He believes that investigating the sneezes may enable us to learn something about certain health problems that involve the brain. That's an intriguing thought.

Sternutation in a Young Elephant

Questions and Answers About Sneezing

How Fast Does a Sneeze Travel?

It's often claimed that sneezes travel at up to 100 miles an hour. This claim originated many years ago and hasn't been confirmed by recent research. It may be incorrect. An investigation performed by a virologist at the Alberta Provincial Laboratory for Public Health found that sneezes travel at 10 miles an hour. The scientist said that his subjects were small framed and that the results may have been different with subjects who had a larger frame. The popular MythBusters TV show found that one person's sneeze travelled at 35 miles an hour and another person's at 39 miles an hour.

Does Our Heart Stop Beating When We Sneeze?

The idea that the heart stops beating during a sneeze is another common myth. It's true that as we sneeze our chest muscles contract. This may momentarily change the rhythm of the heart beat, but it doesn't stop the heart from beating.

Is Sneezing Dangerous?

Sneezing is rarely dangerous for the person performing the activity and is simply an annoyance or a nuisance. Sometimes, though, it can cause problems. Sneezing while driving a vehicle is potentially dangerous because it causes us to close our eyes. Very rarely, in susceptible people a sneeze can cause a stroke or break bones. Another problem is that sneezing can release pathogens (organisms that cause disease), which can be dangerous for other people.

The Sesame Street Sneezing Song

Some More Questions and Answers

Can We Sneeze in Our Sleep?

No, say the experts. When we are asleep, the nerves involved in the sneeze reflex are unable to create the reflex. The reflex pathway is "sleeping," too.

What Is Snatiation?

Sneezing caused by an overfull stomach is genetically controlled and is sometimes known as snatiation. The name is a combination of the words sneeze and satiation. The term was created as a joke, though the behavior may not be amusing for the sufferer. The letters in the name are said to stand for "Sneezing Non-controllably at a Time of Indulgence of the Appetite—a Trait Inherited and Ordained to be Named".

Why Do People Say "Bless You" After a Sneeze?

There are several theories that try to explain how this tradition began, but it's not certain which is correct. It may have begun during the bubonic plague. Sneezing is one of the symptoms of the plague, so perhaps this saying was an attempt to protect the sufferer from death. Other theories suggest that the saying began because people thought that a sneeze could expel the soul from the body, or they believed that it was a sign of a demon leaving the body.

Why Do People Say "Gesundheit" After a Sneeze?

The word gesund is German for healthy. The suffix heit is equivalent to the suffix ness in English. When someone says "Gesundheit" to a person who has just sneezed, they are wishing them health and hoping that the person isn't ill (or at least this was the original meaning of the term).

One More Question: What Was the Longest Sneezing Fit Ever?

Donna Griffiths from England sneezed for 978 days in a row. She began sneezing on January 13th, 1981, and stopped on September 16th, 1983. Her sneezes occurred every minute to start with and then slowed to one every five minutes. She holds the Guinness World Record for her "achievement".

Sneezing sometimes has an amusing aspect, but it can also be annoying, as I'm sure it was for Donna Griffiths. In some cases it can be unpleasant, such as when it's a symptom of disease. It's interesting that even today there are some unanswered and puzzling questions about the process of sneezing.


This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

© 2012 Linda Crampton


Linda Crampton (author) from British Columbia, Canada on May 03, 2013:

Thanks for the comment, moronkee. It's nice to meet you!

Moronke Oluwatoyin on May 03, 2013:

When I inhale dust, it makes me sneeze. Thanks for the lesson.

Linda Crampton (author) from British Columbia, Canada on May 02, 2013:

Hi, FullOfLoveSites. I guess the doctors couldn't help. Sneezing that often would certainly interfere with life! Thanks for the visit.

FullOfLoveSites from United States on May 02, 2013:

What the heck... 978 days... in every minute! Poor lady. A sneeze is just a sneeze but that's was quite an ordeal for her everyday. Didn't she go for a checkup? But I'm glad it mercifully stopped.

Linda Crampton (author) from British Columbia, Canada on January 24, 2013:

Thank you very much for the kind comment, jessdes. I appreciate it. I’ve heard of the suggestion that saying a silly word distracts a person when they feel an oncoming sneeze and can stop the sneeze from happening, but I’ve never seen any research supporting this idea. What often works for me is stretching the area above my upper lip and wiggling my nose around! Good luck with the science fair project.

jessdes on January 24, 2013:

Great article! My daughter is researching sneezing for a science fair project. She is trying to answer scientifically why does saying certain words stop a sneeze. She is only finding silly answers of yelling out "cucumber" as a means of a distraction therefore stopping the sneeze. We believe it has more to do with air intake or put out. If we say a word that pulls air in we sneeze if we say a word that pushes air out we stop our sneeze. Do you have another explanation for this? We would love to hear it. Your videos are great! Thank you for sharing all this was the best information we have found for our project thank you!

Linda Crampton (author) from British Columbia, Canada on January 10, 2013:

Thanks for the comment and for sharing your interesting experience, PaisleeGal. I appreciate the vote, too!

Pat Materna from Memphis, Tennessee, USA on January 10, 2013:

Alicia .. good hub and interesting to know stuff. Being a seasoned sneezer with much experience I appreciate the info. However, I have to question the thing about not being able to sneeze in your sleep. I sometimes will be sound asleep and will suddenly start sneezing. Of course once I start sneezing I am no longer asleep, so I suppose it is partially correct. Anyway thanks for another good hub .. voted up.

Linda Crampton (author) from British Columbia, Canada on August 25, 2012:

Thanks for the comment, Cleanclover. I'm sorry that cold air irritates your nose and makes you sneeze. Getting headaches from sneezing sounds very unpleasant!

Cleanclover from Piece of land! on August 25, 2012:

I sneeze a a lot because I get constantly exposed to cold air. The temperature change makes me sneeze like mad and it's very uncomfortable specially I even get headaches with so much sneezing.

Thank you for this hub it is very interesting and some of the information I did not know. :-)

Linda Crampton (author) from British Columbia, Canada on March 25, 2012:

Thank you for the comment, Sunita-Sharma! It's nice to meet you.

Sunita-Sharma from Los Angeles,California,US on March 25, 2012:

Very interesting hub!Liked it!Thanks for sharing such useful information.

Linda Crampton (author) from British Columbia, Canada on March 15, 2012:

Thank you, Eddy. I appreciate your visit and comment!

Eiddwen from Wales on March 15, 2012:

Great hub Alicia;totally unique and I loved it.

So an up up and away here.

Take care and enjoy your day.


Linda Crampton (author) from British Columbia, Canada on March 14, 2012:

Hi, StellaSee. Yes, the ACHOO syndrome is an appropriate and funny name for a photic sneeze! You're very right about the dangers of sneezing while driving on a freeway. The momentary loss of attention could be all that's needed to create a horrible accident. This is another argument in support of us making sure that we have a lot of space around our vehicles when we drive! Thanks for commenting.

Linda Crampton (author) from British Columbia, Canada on March 14, 2012:

Thank you for my new title, drbj!! I appreciate your comment, as well. Yes, the animal videos are interesting. Sneezing seems to make as big an impression on some animals as it does on us!

StellaSee from California on March 14, 2012:

Haha love the ACHOO syndrome..but in all seriousness, it's really scary when you sneeze while you're driving..especially on the freeway!

drbj and sherry from south Florida on March 14, 2012:

I now anoint you, Alicia, as the Sultana of Sneezing. You are the resident expert whose assiduous research can help us understand the entire process of sternutation.

Loved the animal videos. The baby elephant was so excited by his/her sneeze, and the mother panda was absolutely shocked by her panda cub.

Linda Crampton (author) from British Columbia, Canada on March 14, 2012:

Hi, mary615. Thank you for the visit and the votes! I was glad to find the videos, and the baby elephant was certainly cute. I'm not happy when I need to sneeze, but sneezing is an interesting topic to study!

Mary Hyatt from Florida on March 14, 2012:

Well, this Hub was certainly interesting! I hate to sneeze (almost as much as I hate to hic cup). Loved your video, especially the little elephant. I voted this one UP, etc.

Linda Crampton (author) from British Columbia, Canada on March 14, 2012:

Thank you very much for both the comment and the votes, teaches12345. I agree, the baby panda is adorable, and so is the mother's reaction to her baby's sneeze!

Dianna Mendez on March 14, 2012:

You have made a simple every day thing very interesting! I learned a lot from your hub such as the rate of travel (100 miles per hour! Wow!). I love the baby elephant video, but the panda was so adorable. Voted up and awesome!

Linda Crampton (author) from British Columbia, Canada on March 14, 2012:

Thanks for the visit and the comment, Emma. The sneezing panda video is very funny, although I don't like the look of the cage that encloses the mother and baby. I actually prefer watching the sneezing baby elephant, since the elephants are free to roam.

Linda Crampton (author) from British Columbia, Canada on March 14, 2012:

Hi, DzyMsLizzy. Yes, I suffer from hay fever too, and it's very annoying to be helplessly sneezing during allergy season! It really interferes with what I'm trying to do. I haven't thought about the sound of the word "sneeze" before. You're right, it does sound funny! Thank you for the votes.

Emma Kisby from Berkshire, UK on March 14, 2012:

Very interesting hub and very detailed.

I had heard that sneezing with out eyes open would make them pop out, but questioned whether or not is was true. Closing them or blinking is probably a reaction.

I love that baby panda on YouTube as well - always makes me giggle whenever I watch it.

Liz Elias from Oakley, CA on March 14, 2012:

Very well researched and interesting. As a hay-fever sufferer, I've done my share of sneezing, and it is, indeed, annoying. I find that sneezes always come in pairs, or multiples thereof. When something is in the air and you sneeze a dozen times in a row, it is maddening.

That slow-mo video was, well... "eeewww!" The animal ones were funny.

On the other hand, "sneeze" is itself a funny-sounding word, and I recall sitting around, as a child with my friends, saying the word over and over until we laughed ourselves silly.

I enjoyed the article. Voted up across the board.