- Sneezing is a reflex that helps expel pollen, dust, and other irritants from your nasal passages.
- Your brain prevents reflexes in NREM sleep and muscle movements in REM sleep, so you can't sneeze.
Sneezes happen as a reflex, or involuntary response, which is why it often feels impossible to hold them back. They help your body clear out irritants like pollen, dust, and chemicals.
But you can't sneeze during sleep – something you may have already realized for yourself if you've ever struggled to rest during a bad cold.
When you sleep, your brain shuts down your body's reflex responses like sneezing and coughing. So, when your body has to sneeze, it will wake up, says Dr. Po-Chang Hsu, a medical writer, consultant, and content expert at Sleeping Ocean.
Read on to learn why you wake up to sneeze and what to do about frequent nighttime sneezing.
Note: Though you might consider sneezing inconvenient or even a little embarrassing, it's generally best to let it happen. Consistently suppressing sneezes can cause mucus buildup, a middle ear infection, or damage to your eardrum.
Why you can't sneeze during sleep
Your body suppresses sneezes in two different ways, depending on which phase of sleep you're in.
Sleep is divided into two phases: non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep, the phase of sleep in which you dream. You cycle through these phases throughout the night.
During NREM sleep
NREM sleep, which comes first, has three stages:
- Stage one: This lightest sleep stage lasts from one to five minutes.
- Stage two: In this stage, your heart rate and temperature drop as you fall into a deeper sleep. The first cycle of this stage lasts about 25 minutes, with each later cycle lasting longer.
- Stage three: This deepest stage of sleep is difficult to wake from. You'll feel groggy if something happens to wake you up during this stage before it ends naturally.
During NREM sleep, your body's sensory and reflex system continue to operate, but they're much less sensitive. This is why you can sometimes sleep through a loud noise or why someone might need to shake you awake.
In the same way, things that might normally trigger a sneeze, like dust or pollen in the air, will have a much harder time getting the attention of your brain during NREM sleep.
You could wake up during one of the lighter stages of sleep to sneeze if the stimulus is strong enough — like a gust of wind blowing pollen through an open window — but you won't sneeze as long as you remain asleep.
During REM sleep
You can't sneeze during REM sleep because a temporary state called motor atonia leaves your body paralyzed when you dream. Basically, your brain shuts down your body's ability to move to prevent you from acting out what's happening in your dreams.
Sneezing requires the coordination of multiple muscles, and since your muscles can't work when your brain puts you into a state of motor atonia, it is not possible to sneeze during REM sleep, Hsu says.
What causes night sneezing?
A sneeze is your body's protective response to irritants in your nasal passage. When something foreign — whether dust, pollen, or a virus — enters your nasal passages, a sneeze serves to get rid of it.
You might sneeze more often at night for two main reasons.
First, lying down increases blood flow to your nasal passageways. As a result, you produce more mucus, which increases the likelihood of sneezing, says Dr. Harold Hong, medical director at New Waters Recovery.
The second cause lies in your sleeping environment itself. A number of allergens in your bedroom might cause you to sneeze, with common culprits including:
How to prevent nighttime sneezing
If you can't fall asleep at night because of frequent sneezing, or if you often wake up to sneeze, you may be experiencing an allergic reaction.
A good first step might involve eliminating any potential allergy triggers from your bedroom. Try these seven tips:
1. Reduce pollen in your bedroom: Keep your windows closed, especially on high pollen days, and run an air purifier.
2. Keep your bedding clean: Experts recommend washing sheets once per week and pillowcases every two days with the hottest water possible. You can also consider using an allergy barrier bed cover to reduce your exposure to any allergens coming from your mattress.
3. Don't let pets onto your bed: Pet dander on your bedding can cause nasal irritation and sneezing. If you really like having a pet in your bedroom at night, try setting up a separate bed for your cat or dog.
4. Keep your bedroom clean: Vacuuming, dusting, and cleaning surfaces in your bedroom once or twice per week can help cut down on dust and dander that might trigger sneezing.
5. Try showering at night: A quick rinse before bed can help remove any dust and pollen from your skin and may even promote more restful sleep.
6. Check for mold in your home: Evaluate your home for the presence of mold by visually checking dark and damp areas and paying attention to any musty smells. If you think you have a mold problem, clean areas with mold thoroughly and then use a dehumidifier.
7. Try a neti pot: You can use a neti pot — a device to hold sterile water that you pour through your nostrils — or a saline rinse before bedtime to clear your sinuses and reduce irritation, Hong says.
If none of the above tips help and you're still waking up frequently to sneeze, you may want to connect with an allergist or immunologist to learn more about your treatment options, which might include medication or allergy shots, Hong says.
Insider's takeaway
Sneezing helps your body get rid of irritants in the nasal passage, but sneezing in your sleep is not possible — you will wake up if you need to sneeze.
If you often sneeze at bedtime or wake up to sneeze in the middle of the night, you could be dealing with allergies.
Taking steps to remove allergens from your bedroom could make a difference, but if that doesn't help, a good next step involves checking in with your doctor. They can help you pinpoint potential causes of your sneezing and recommend treatments to improve your rest.