Does Sneezing stop our Heartbeat?
Let us first look at what scientists think about how and why we sneeze. Sneezing starts with our nerves. They sense irritations it might be dust, any sort of mechanical stimulation in the nose, or even the chemical called histamine that our immune cells make during allergy and lead to what is called a sneeze reflex - a coordinated function of several muscles in our head and upper body. We inhale deep, close our mouth and nasopharynx (front part of the throat) - this helps builds up air pressure in our lungs. Next the brain coordinates contraction of several muscles, causing forceful expulsion of the air, at high speeds that often reach 100 miles per hour. Basically, a sneeze is our body's way of cleaning our nasal passage.
Well, coming back to our question about heart, it is obviously not true that sneezing stops our heart permanently, or we will all be dead now. But it does slow down our heart due to the increased air pressure in our chest. This is a temporary change and is corrected once the sneezing stops. All these changes are regulated by brain nerves that control our heart, chest and abdominal muscles, and diaphragm all function together to execute a successful sneeze and it is not surprising that the heart rate is regulated by the function of other muscles as well. However, prolonged sneezing or a bad heart condition can often cause defective blood flow to brain leading to temporary loss of consciousness. This is called the sneeze syncope.
Suppressing sneezing may be bad for health only if you are unlucky the increased pressure can burst eardrums, break blood vessels in brain or even clot blood in small blood vessels. Violent sneezing can also create a few problems. However for normal people sneezing is good for health. It is important for keeping our nasal passage clean and healthy. But it is better to be hygienic while we are at it. Sneezing is a common way to spread a lot of bugs around a single sneeze can release up to 40,000 small drops of nasal secretions (source: wikipedia), and that's not nice to others. Several bacteria that cause diseases, including meningitis and tuberculosis, are often spread through sneezing.
Sneezing is not always associated with nasal irritation or allergies, but can be genetic as well. Several people carry a trait called photic sneeze reflex that makes them sneeze when looking at very bright light. Another rarer condition is snatiation where sneezing is induced by the fullness of a large meal.
Is there a way to prevent sneezing? There are several suggestions that we often hear: holding our breath or even expulsion of the air that is needed for a sneeze and even pinching the tip or bridge of the nose. However a better way is to avoid the stimulus for the sneeze the dust or pollen, for example, or to use medicines such as Antihistamines that prevent allergic reactions. Another way is to induce sleeping people who are in the REM phase of sleep do not sneeze unless the stimulus is strong enough, and even then they wake up to sneeze. Strangely, some people find sneezing pleasurable and often don't feel any need to avoid them.
Written by : Sujatha S., Canada (PHD Life Sciences)
Edited by: Rajesh Bihani ( Find me on Google+ )