When it comes to sleep science, there are plenty of odd facts that highlight just how complex and fascinating the human body really is. One particularly strange discovery? You can’t sneeze while you’re asleep. That’s right even if your nose is tickled by dust or allergens, your body’s ability to sneeze actually shuts down during certain stages of sleep. But why does this happen, and what does it tell us about how sleep affects our nervous system?
To understand why sneezing doesn’t occur during sleep, it helps to look at how a sneeze actually works. Sneezing is a reflex triggered when something irritates the nasal mucosa typically dust, pollen, or other airborne particles. This irritation sends a signal through the trigeminal nerve to the brainstem, which responds by initiating the powerful expulsion we know as a sneeze.
However, during sleep especially deep non-REM sleep your body’s sensory responses are significantly dampened. According to research published in the Journal of Physiology, the thalamus (a key part of the brain that relays sensory information) reduces its activity during sleep stages, limiting the ability for external stimuli to be fully processed. This means even if your nasal passages are irritated, your brain may not receive the signal strongly enough to produce a sneeze.
Additionally, during REM (rapid eye movement) sleep, the body enters a state of temporary paralysis known as REM atonia. This natural state helps prevent you from acting out your dreams. Since sneezing involves coordinated muscle contractions from your diaphragm to your throat and facial muscles the muscular inhibition during REM sleep further prevents a sneeze from happening, even if the brain were to detect an irritant.
Another reason you’re sneeze-free while snoozing involves neurotransmitters. Studies from the National Institutes of Health show that neurotransmitters like serotonin and norepinephrine drop significantly during REM sleep, further inhibiting reflexes such as sneezing or coughing. Essentially, the brain dials down both sensation and motor function during sleep, especially in REM, keeping involuntary responses in check.
Interestingly, while you can’t sneeze during sleep, you might wake up and sneeze if the irritation becomes strong enough to rouse your brain. This is why people with allergies or respiratory issues may find themselves waking up in the middle of the night to sneeze or blow their nose but they’re no longer technically asleep when the sneeze occurs.
This weird little sleep fact isn’t just a quirky bit of trivia. It’s a reminder of how profoundly our brains and bodies shift during sleep. The systems we rely on for wakeful reflexes are placed on pause, allowing for rest and repair but also limiting certain functions until we’re awake.
If you suffer from nighttime nasal congestion or allergies, addressing these issues before bed can help improve your sleep quality. Using a HEPA filter, avoiding allergens, or trying a saline nasal spray can reduce the chances of waking up in the night due to irritation.
Sleep is full of surprises, and the fact that you can’t sneeze during it is just one more way our bodies prioritize rest above all else.
Sources:
Journal of Physiology – Sensory attenuation during sleep
National Institutes of Health – REM sleep and neurotransmitter activity
Sleep Research Society – Muscle atonia in REM sleep
American Academy of Sleep Medicine – Sleep-related breathing facts
Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. If you have concerns about sleep disturbances, allergies, or other health issues, please consult a healthcare provider.