Sneezes occupy the attention of flu mavens because the aerosol created is likely one of the chief ways the virus finds a new host. So it's a selective advantage to a respiratory virus to make someone explosively expel air from the lungs through the nose. A sneeze even has a medical name: sternutation. The speed of the estimated 40,000 aerosol droplets has been variously given as 90 to 650 miles per hour.
But sneezing is a complex act and lots of things can make someone sneeze besides the flu or a head cold. Things that irritate the nose cause some people to sneeze. And there is an inherited (autosomal dominant) response called the photic sneeze reflex where stimulating the optic (2nd 3rd cranial) nerve with a bright light seems to make a reflex arc to the trigeminal (5th cranial) nerve, which controls sneezing. It's not even particularly rare. One estimate says it affects a quarter of the population. A full stomach makes other people sneeze. I know someone who sneezes after meals.
And then there's sneezing when thinking about sex:
Dr Mahmood Bhutta, an ear, nose and throat specialist at the John Radcliffe Hospital in Oxford, launched the study after seeing a patient who suffered "uncontrollable" sneezing fits every time he had a sexual thought."We thought this unusual and performed a literature search of the topic," he wrote in the Journal of the Royal Society of Medicine. Together with colleague Dr Harold Maxwell, Dr Bhutta found that typing the words "sex", "sneeze" or "sneezing" into Google produced a surprising number of hits. "Although internet reports do not give us an accurate incidence, our findings do suggest that it is much more common than recognised," wrote Dr Bhutta and Dr Maxwell.
[snip]
Dr Bhutta said he believed sneezing when thinking about sex probably ran in families too. He added: "I think this reflex demonstrates evolutionary relics in the wiring of a part of the nervous system, the autonomic nervous system... Sometimes the signals in this system get crossed, and I think this may be why some people sneeze when they think about sex." (Nothing to do with Arbroath)
Deep thought: for some people is flu a venereal disease where you don't even have to have sex with the person to catch it?
Medicine & Health
Comments
Hiccuping is very interesting, too. While sneezing plays an obvious physiological role--expelling boogers from the upper respiratory tract--hiccuping doesn't seem to have a purpose.
Posted by: Comrade PhysioProf | December 25, 2008 12:38 PM
I've been trying to convince people for years that sexual thoughts--especially "unbidden" ones--can trigger a sneeze. I actually noticed this when I was a teenager (and therefore sneezing around the clock) but dismissed it as coincidence until reading about the phenomenon years later in some lay science mag.
So I continue to be vindicated. And perennially single.
Posted by: kemibe | December 25, 2008 2:06 PM
Minor nitpick: the optic nerve is C.N. II, not the 3rd cranial. C.N. III is the occulomotor.
Posted by: c-serpent | December 25, 2008 2:21 PM
So it's not just me? This is the first I've ever heard beyond my own experience.
Maybe this explains (family lore will now be revealed) why my mother used to sneeze vigorously and in nearly the same breath exclaim, "Whoooppieeee!"
It seems to make sense that such basic functions as respiratory and sexual function are influenced by more primitive parts of the brain and therefore some overlap might be expected. Both functions have been around for at least as long as brains have.
AAaaaCHOOooooo!
*whoopie*
S'cuz me, but it seems to work in reverse, too. That is, I don't recall ever sneezing while having sex, but I often sneeze while thinking about sex. At any rate, fascinating. Thanks.
Posted by: Crudely Wrott | December 25, 2008 4:44 PM
c-serpent: Not so minor a nitpick. My mnemonic failed me (both O's) 40 years after taking neuroanatomy. Thanks. Corrected.
To all the others, from an atheist: God Bless you! LOL.
Posted by: revere | December 25, 2008 5:02 PM
I thought hiccuping was supposed to be a vestigial gill-breathing reflex. Sorry, can't find the link for this.
Posted by: outlier | December 27, 2008 10:18 AM
We were not aware that sneezing had anything to do with sexual pleasures or tendencies and that they had anything to do with one or the other.
Posted by: Siera Burtonn | February 9, 2009 12:54 PM
I always sneeze when I think about sex. usually 2 or 3 sneeze come quickly.
Posted by: Dave | February 16, 2009 2:06 PM
About the following:
"Dr Mahmood Bhutta, an ear, nose and throat specialist at the John Radcliffe Hospital in Oxford, launched the study after seeing a patient who suffered "uncontrollable" sneezing fits every time he had a sexual thought."
How did he know that the patient had sexual thoughts before every sneeze?
Posted by: Alex | February 2, 2010 11:41 PM
Alex: case report. May or may not be 100% accurate (or reported accurately) but apparently the phenomenon is real. Lots of autonomic nervous system involved, so it isn't implausible.
Posted by: revere | February 3, 2010 8:13 AM