I can’t tell you how many times my girlfriend complains in the morning about all of my sneezing throughout the night while I’m asleep. That’s actually not true, and not only because I’m devastatingly single and I have no one to complain about my hyperventilating at night (it rarely happens) or punch me in the face because I’m snoring too much (what kinds of relationships have I been in???).
In fact, it is impossible to sneeze while you are sleeping!
When you are awake, particulates, allergies, illness, plucking your eyebrows, sex, or sunlight (more on the last two later on) can stimulate the nerve cells in the nose, which send a signal to the lower brain stem. The brain causes the chest to tighten and throat to loosen, thus beginning the sneezing process, which is an important immune response. Yay!
But why don’t we sneeze when we sleep?
Indeed, you are more prone to sneezing when you lie down because the mucous membranes swell and become more sensitive when you do so. However, there isn’t normally as much airflow or movement of particles and stimulants to trigger the sneezies. Phew, it’s a good thing I don’t sleep in a breezy dandelion field!
Oh, but wait! Even a dandelion field won’t trigger a sneeze while you are asleep, assuming you can fall asleep to begin with. During REM (rapid eye movement) sleep, REM atonia occurs, which is the shutting down of certain neurotransmitters. This means the motor neurons in the nose are not being triggered, thus the brain is not notified of the need to sneeze. . . until you wake up.
Even when your girlfriend blows pepper up your nose to stop your snoring (who have I been dating??), you won’t sneeze until you’re awake. Cool!
What was that I was saying about sunlight and sex? Two topics people love to talk about equally, I would say. Sneezing can occur among some people during sexual relations. It is believed that the signals in the autonomic nervous system, which is in charge of our heart rate and amount of light the pupils let in, can become crossed and cause tissue in the nose to engorge in a small percentage of people, which causes them to sneeze during sex or even when they think about it. Bright sunlight can also cause one in three people to sneeze. These people are referred to as photics, or sunlight sneezers, as I prefer to call them. Sunlight sneezers inherit this curse from their parents.
Speaking of sunlight, don’t you hate it when you’re driving toward the sun and the glare is blinding you, especially when you’re already carsick*? (wow, I’m like the king of segues!)
Now, I’m not a sexual or sunlight sneezer, but I do suffer from motion sickness on a pretty regular basis. While I have made myself carsick when I was driving myself, that is pretty rare for me. Normally it occurs when I’m a passenger with a really jerky or swervy driver, or if I’m on a mountain road, or if I cannot see the road because I’m sitting in the back, or if I’m on a bus, or a train, sometimes a plane. . . so all the time.
I discovered something on a recent trip through the Grapevine, which is a stretch of freeway in central California. I have ear pressure issues on steep ascents or descents, and the Grapevine is a place where this occurs regularly for me. On top of that, I was sitting in the back of a vehicle with unusually large front seats that prevent easy view of the road. That is an instant recipe for motion sickness for me. However, on this occasion, I fell asleep during the worst part of the drive.
Disclaimer: sleeping is only recommended if you are not the driver
When I awoke, I found that I was not at all motion sick. I thought this to be rather surprising. Allow me to explain.
It is believed that motion sickness occurs when there is a conflict between what your eyes are seeing and how your body is interpreting the external stimuli and motion, by sitting in the back of the car, for example (hint hint people driving with me and calling shotgun). This causes inner ear issues and your equilibrium can be thrown off.
I found it unusual that sleeping would prevent motion sickness because at that point my body would feel all of the motion and curves of the road and there would be no visual information to settle the conflict. My vision is telling me no. But my body, but my body is telling me yes!
It turns out, that sleeping is a fantastic cure for motion sickness. Sleep is great! Then why don’t I get more of it?
It turns out that you don’t experience motion sickness while you are sleeping simply because your brain is not aware of the differences between the visual information and the signals your body is sending. Unlike sneezing, nothing seems to shut off during sleep with regard to motion.
Well that was fascinating information about how sleeping affects motion sickness and sneezies (I have never in my life said sneezies, and yet now I cannot stop). I hope you found it as fascinating as you should find it. Tune in next time for more fun facts!
*carsick - motion sickness while in a car (I had to clarify because many people haven’t heard that term)
Author and hobby digital artist. Barry loves useless trivia and learning new, interesting facts.