The interesting science behind sneezing

Sneezing is something that everybody experiences. While it’s such a common occurrence, not many really understand the science behind it. Many may even be surprised to find out that yes, there’s a scientific explanation behind it.

Sneezing usually results from irritants in the respiratory epithelium lining inside the nose. It’s a physiology reaction to this irritation. The entire process is initiated when leukotrienes or histamine is released. These two are chemicals which are synthesized by inflammatory cells including mast cells and eosinophils. The inflammatory cells are located within the nasal mucosal.


The production of these chemicals can be as a result of several causes. These include allergens which are substances that encourage allergic reactions, filtered particles and viral respiratory infections. It may also be triggered by physical irritants such as perfumes, cold air, pollution and smoke. Allergic reactions of the nasal mucosal are characterized by congestion and nasal drip. This results from the leakage of fluids from vessels found in the interior of the nose. It also causes itching, which happens when the nerve endings are stimulated.

It’s the stimulation of the nerve endings that eventually leads to a responsive reflex in the brain. The rapid expulsion of air experienced during sneezing happens when the nervous impulse travels through the sensory nerves, then down nerves that control the muscles found in the head and neck. Closed vocal cords lead to increased pressure within the chest. This builds up the speed of airflow which results in a sneeze. When these cords are suddenly opened, the pressurized air is let back up the respiratory tract. This is aimed at expelling the irritants that are causing the chemical release in the first place.

This is how infections such as common cold are spread. The expulsion of air removes the irritating particles, including viral ones. That’s why it’s always advisable to cover your mouth and nose while sneezing, with a piece of cloth. Many people don’t really seek medication for sneezing. In fact, many may not be aware that there are treatments for sneezing. While for some people sneezing is a once in a while occurrence, for others it’s an everyday reaction. This is because people are affected by different types of allergens.


Antihistamines are one of the drugs used to control the reaction that leads up to sneezing. They provide relief for the symptoms that accompany allergies, such as runny nose, itching and nasal congestion. These drugs work by inhibiting the function of histamine receptors in the inflammatory cells of the nose. Since this is the chemical that initiates the process that leads up to sneezing, they’re effective in curbing the reaction.

Topical nasal steroids on the other hand reduce inflammatory cells in allergic patients. This ultimately stops the secretion of histamine. The other type of medication used are decongestants. These are drugs used to get rid of the nasal congestion in parts of the respiratory tract. They do this by stimulating the receptors in the mast cells to constrict, easing up on the congestion. Sneezing can be prevented by avoiding the irritants that trigger the allergic reaction.