Sneezing is a body reflex usually triggered by outside stimuli, most often some kind of irritant to the nasal system. However, can you sneeze in your sleep? Have you ever thought about it?
Before we get to the answer, first we need to understand how sneezing occurs and the causes of sneezing. Sternutation as sneezing is also referred to, is an involuntary expulsion of air from your lungs, triggered by irritants affecting nasal mucous, through the mouth and nose.
Why and how do we sneeze in the first place?
Once the nasal system smells irritants within it, pun intended, a process is immediately signaled which is meant to get rid of whatever may be causing the disturbance. As soon as foreign matter comes into contact with the mucous membrane, they trigger the secretion of histamines, which irritate nerve endings in the mucous membranes to send signals to the brain about the intrusion.
Once the message reaches the brain, the process of extraction begins with the brain signaling pharyngeal and tracheal muscles for a sneeze. They open up the airways of the nose and throat to force out the irritants, thus sneezing.
Common causes for sneezing include:
- Allergens; basically, things which will cause an allergic reaction such as dust and pollen.
- Non-allergenic foreign particles which irritate the nasal mucous membrane and trigger sneezing.
- Illnesses connected to the nasal cavity such as the common cold and flu.
- Photic sneeze reflex is a condition where sneezing is triggered on exposure to bright light suddenly and occur in about 35% of the human population
- Some people sneeze during digestion, especially after a heavy meal. It is a rare genetic disorder called Snatiation.
Now, the answer to your question- Can you sneeze in your sleep?
Even though sleep offer almost perfect conditions for you to sneeze, this reflex, like many others, are suppressed when we are asleep. In certain positions, the mucous membrane swells such as lying on the back, side or stomach like we do when sleeping. But, why don’t we sneeze?
Sleep comes in two phases, rapid eye movement sleep (REM) and non-REM sleep with the former taking up to 25 percent of your sleep. In other words, unless interrupted, you will be in REM for twenty-five percent of your sleeping time.
Sneezing impulses are suppressed through rapid eye movement (REM) atonia at which time allergen detecting neurotransmitters shut down thus preventing sneezing. Much like hunger and thirst are suppressed, the process is the work of the brainstem disconnecting higher brain functions of the cerebral cortex.
Sleep is divided into five stages and REM atonia is exclusive to Stage 5 where brain neurotransmitters shut down. When this happens, the motor neurons responsible for sneezing will not react to irritation of the nasal cavity.
The five stages of sleep
Stage 1 sleep
This is light sleep where you are easily disrupted and can be woken up easily. There are slow eyes movement and reduced muscle activity. Some people experience muscle contractions.
Stage 2 sleep
At this stage, eyes movement stops and brain activity slows down. The heart slows and the body begins to cool down and temperatures drop waves become slower. The body is getting ready for deep sleep and this is one of the reasons why cooling mattress pads have become so popular.
Stage 3 sleep
Slow brainwaves, also known as delta brain waves intersperse with rapid brain waves to cause the onset of deep sleep and is the boundary between non-REM and REM sleep. Sleep disorders such as wetting the bed and sleepwalking happen at this stage.
Stage 4 sleep
Delta waves are all there is for brain activity. This is the slow brain wave sleep and if you are disrupted from sleep at this stage you will face deep disorientation.
Stage 5 sleep
This is REM sleep where brainwaves begin reverting to waking activity. The eyes dart side to side but remain closed and the majority of your dreams happen at this stage of sleep. This last stage of sleep takes about an hour and a half with successive REM sleep cycles lasting 100 to 120 minutes.
Understanding the REM atonia and sneezing connection
Sleep is naturally induced through the body’s internal clock which is instinctively responsive to light and darkness, day and night. The circadian clock triggers sleep when it gets dark outside and gets you awake when the sun comes up using the sleep-inducing hormone melatonin which is secreted at night and shuts down with sunlight.
Patterned on the production and shutting down of melatonin and ho it tapers off during sleep, the circadian rhythm, ensures five sleep stages, four which are non-REM sleep, the majority of sleep time.
This then begs the question why you do not sneeze in the first four stages of sleep if REM atonia is a stage five process?
Read more: 9 Top Benefits of Sleeping Without a Pillow
Surprised by the information you have learned about sneezing and sleep? Well, this is an area that has not seen a lot of research, fortunately, there are a lot of studies on sleep and the brain which will open our eyes more about what happens when we sleep.
We should be able to understand better why certain functions of the body like sneezing are put in abeyance while we sleep and others carry on, as well as the parts of the brain responsible. In the meantime, look at it as if the brain cannot be asleep and active at the same time, thus the shutdown of some functions. However, for sneezing, with strong stimuli in the early stages of sleep, you will be woken up to sneeze.
Can you sneeze in your sleep? You now have the answer to that as well as what happens for you to sneeze. You now know about the role of REM atonia and the role it plays with the body’s reaction to irritation of the nasal passage as you sleep. Sneezing requires the action in concert of many muscles and with some on sleep shutdown, when you are deeply asleep, you will never sneeze.
Find more insights here: