WHAT’S IMPORTANT to know about the sneeze is: never try to stop one. Squeezing the nostrils risks a sudden rise in blood pressure in the brain that could cause a stroke or, at the least, a busted eardrum. And keeping the mouth closed can direct the sneeze’s force against membranes of the nose and middle ear, risking congestion, pain, nosebleeds and ringing in the ears.
At the other end of the spectrum, releasing the sneeze — i.e., sneezing — is reputed to lead to orgasm, especially the magic number of seven sneezes. And sneezing during or following sex is not uncommon, perhaps due to the stimulation of the parasympathetic (involuntary) nervous system involved in both sex and sneezing. Other sneeze-producing stimulations are strong odors and sudden chills.
Even without the sexual connection, the pleasure of sneezing for some is evident in the popularity of snuff, among both women and men until its social acceptance waned, and among many sniffers today.
Sneezes can spew from 2,000 to 40,000 droplets of moisture, moving anywhere between 70 to 100 miles an hour, and containing up to 100,000 bacteria and viruses that can remain in the surrounding air for up to 45 minutes. Although most of these germs are benign, sneezers are advised to direct their sneezes into the crook of the elbow to catch as much as possible. Sneeze-free periods occur only during REM sleep when reflex signals are dulled.
The most common causes of sneezing are allergies, followed by colds. Environmental triggers from pollen to dust to dry air and any kind of foreign particle or irritant — black pepper for some— entering the nose can all provoke a sneeze. Exercise causes sneezing when dry air makes the nose run, and genetics are responsible for both photic sneezes, in response to sunlight, and sneezes due to a full stomach after a large meal.
Emotions, especially when repressed, can emerge as sneezes. Fear can cause the nasal membranes to shrink, while frustration, apprehension, grief, anguish and resentment can cause these membranes to swell. Excitement and joy provoke sneezing through the same stimulation pathways as sex. In one medical journal report, treatment-resistant sneezing was blamed on psychological factors in 31 of 38 cases. Likewise, folk remedies to stop sneezing —pressing on the upper lip or sniffing garlic, witch hazel or alcohol — probably work when they do via the emotions rather than for physical reasons. Anti-anxiety medication can also help.
Producing a sneeze involves muscles from the eyelids to the diaphragm. Sneezes begin with a signal from the nose, where stimulated nasal mucosa causes the release of histamines that irritate the nose’s nerve cells. The signal travels down to the brain stem, causing the chest muscles to expand, the diaphragm to contract and the lungs to fill with air; muscles in the throat, eyes and mouth also contract. Then the chest muscles contract, the throat relaxes, and air is forced out of the body through the mouth and nose, sometimes explosively.
To clear irritants from the airways, sneezes sometimes come in threes: number one loosens or dislodges the offender; number two gets it to the front of the nose; and out it goes with number three. Although the sneezing signal closes the eyes, it’s possible to purposefully keep them open, for example while driving. The force of sneezing can sometimes be lessened safely by strongly exhaling air from the lungs through the mouth prophylactically or by massaging the neck or abdomen.
Because the system of trigeminal nerves throughout the face that can play a role in initiating sneezing is close to the optic nerve, signals from two can cross, called “cross talk,” so that, for example, plucking the eyebrows can spur a sneeze.
Though rare, the greatest dangers from sneezing are strokes in people with weakened blood vessels and epileptic seizures in those with a history of epilepsy — though it’s possible for sneezing to be the result and not the cause in both cases.
The sneeziest animals are iguanas, who sneeze to rid their bodies of excess salt. Sneezing is common among mammals as a primitive reflex to protect the nose by eliminating foreign objects that could interfere with the passage of air. The longest human sneezing attack lasted 978 days.
Finally, sneezes have given rise to myths and rhymes. From the days when it was thought that a posey, or sac of herbs, worn around the neck protected wearers from the plague comes Ring-around-a-rosy, with rosy referring to a rosy rash and ending with sneezes “atches, atches [sneezes], we all fall down” — dead.
Another rhyme is thought to refer to the legend that multiple sneezes in a row can end in spontaneous orgasm: “Once — A wish; Twice — A kiss; Three times — A letter; Four times —Something better.” The God-bless-you given sneezers comes from the belief that the sneeze is a near-death experience; the blessing should prevent death by keeping the soul from leaving the body.