From "harbinger of death" to "divine gift": sneezing is perhaps the common physiological reaction that most rare theories have generated
Hebrew tradition tells that, just before biting the apple, Adam sneezed. At the time, it seemed that he did not worry much, but after the one he got involved with the happy fifth piece of fruit a day, he ended up interpreting it as "a sign of evil and an omen of death". The riot was there, of course, and when the very old Jacob worried that he would not see his son, he begged God to change the natural order of things, lest a bad sneeze take him to the other neighborhood.
This is where it comes from (collected or perhaps invented again by medieval tradition) that we want "health" in Spain, "saúde" in Portugal or "Gesundheit" in Germany for someone who has just sneezed. As if to drive away bad omens; that life is not enough to gamble on the dice. However, by common, it is still surprising what a simple sneeze has come to mean.
A faithful companion that we have not always known how to understand
Aristotle, explains García-Moreno, was convinced that, compared to flatus or belching, the sneeze was the only one that had a 'sacred nature' because it came "from the main and deepest and most divine organ, the one that contains the spirit " Hippocrates, on the other hand, although he did not decide on the goodness or badness of the sneeze, did describe the principle of reciprocal inhibition when pointing out that sneezing was, look at what things, the best remedy for hiccups.
As I was saying, the history of sneezing in the West cannot be understood in all its complexity without the black plague. It was then that the "health" of the Judaic tradition or the "Jesus" of the Christian tradition became popular again as a way of wishing that this 'achís' was not the doorway of the cursed plague. The "God bless you" that still resonates in English formulas ('bless you') comes, it seems, from one of the many plagues that plagued medieval papal Rome.
By cons, in many other places, sneezing was considered a good thing. Fantastic. Traditional Hindu medicine used to provoke it as a way to balance internal humors and treat diseases while the most archaic African medicine used it protopsychiatric as a way to cure mental illness (supposedly caused by the existence of worms in the brain). To finish, to end at some point, the Aztecs used it for headaches.
But what is a sneeze?
Actually, a sneeze is a very simple thing. It is a reflexive, sudden and compulsive act, whose purpose is to expel large amounts of air through the nose and (sometimes) also through the mouth. It is, therefore, a physiological reflex that defensively uses the respiratory system. Therefore, it is common for it to occur when certain foreign particles irritate the nasal mucosa. And yes, I have used "habitual" with all the intention in the world.
Apparently, and these are average estimates, before each sneeze we inhale about two and a half liters of air. That is the first phase, the inhalation. At that time, the abdominal muscles tighten the diaphragm to increase the pressure in the lungs and get air to come out of the nose at a breakneck speed: between 70 and 130 kilometers per hour.
The saliva that is usually expelled with the sneeze can cover an area of up to 8 square meters. And it is precisely this that makes sneezing one of the worst vectors of disease spread in the world. However, sneezing is most popular precisely when it is most harmless: in spring, summer, or fall.
When caused by 'allergic rhinitis'. A classic, in fact. This type of rhinitis, caused by the pollen of trees, weeds and grasses, becomes the great recurring character in the life of practically a third of the population. It is insufferable, unbearable, a cross. But still and still, there are worse sneezes.
Between 18 and 25% of the population suddenly sneezes when exposed to bright light. It's what's known as a 'photic sneeze' and it's an old acquaintance (and a cause of disability) of aviation pilots. Apparently it is hereditary and is produced by an anatomical closeness between the second cranial pair (the eye, responsible for bringing visual information to the brain) and the fifth (the trigeminal, which seems to be responsible for sneezing).
When there is very bright light, excitation of the optic nerve can cause trigeminal excitation. This signal is interpreted as irritation of the mucous membranes and displays a beautiful, annoying and enormous sneeze. Something similar (although linked this time to the medulla oblongata) may be behind people with a natural tendency to sneeze after eating, when they see something pleasant, or even during orgasm. It is already a bad leg, although well used (and in this even Aristotle would agree) it can be seen as a "wonderful" way to improve communication in the bedroom.