During sleep, the brain turns off the body's reflex responses such as sneezing and coughing. So when the body has to sneeze, it wakes up, says Dr. Po-Chang Hsu, a medical writer, consultant, and content expert at Sleeping Ocean.
As we know, sneezing itself occurs as a reflex, or involuntary response. So it's impossible to hold on. In fact, sneezing can help the body wash away irritants such as pollen, dust, and chemicals.
Sneezing may feel uncomfortable or a little embarrassing. However, the best course of action is to let it happen. Consistently holding back a sneeze can lead to mucus buildup, middle ear infection, or damage to the eardrum.
The body suppresses a sneeze in two different ways, depending on the phase of sleep. You go through these phases all night long.
There are two phases in sleep, namely non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep, the sleep phase where you dream.
NREM sleep
NREM sleep, which comes first, has three stages:
Stage one:
This lightest stage of sleep lasts from one to five minutes.
Stage two:
At this stage, your heart rate and temperature drop as you fall asleep more deeply. The first cycle of this stage lasts about 25 minutes, with each subsequent cycle lasting longer.
Stage three:
This deepest stage of sleep is difficult to awaken. You will feel dizzy if something happens to wake you up during this stage before it ends naturally.
During NREM sleep, your body's sensory and reflex systems continue to work, but are less sensitive. This is why you can sometimes sleep through loud noises or why someone might need to wake you up.
In the same way, things that normally trigger sneezing, such as dust or pollen in the air, make it harder to get your brain's attention during NREM sleep.
You may wake up to a sneeze during one of the lighter stages of sleep 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 stay asleep.
During REM Sleep
You can't sneeze during REM sleep because a temporary state called motor atony makes your body paralyzed when you dream. Basically, your brain turns off your body's ability to move to prevent you from acting out what happened in your dream.
Sneezing requires the coordination of multiple muscles, and because muscles can't work when your brain puts you into a state of motor atony, Hsu says it's impossible to sneeze during REM sleep.
You may sneeze more often at night for two main reasons. First, lying down increases blood flow to the nasal passages.
"As a result, you produce more mucus, which increases the likelihood of sneezing," says Dr. Harold Hong, medical director at New Waters Recovery, told Insider.
The second cause lies in your sleep environment itself. A number of allergens in the bedroom may cause you to sneeze, with common causes including: pet dander, pollen, mites, dust.
Prevent Sneezing
Sneezing that goes on frequently at night will certainly make you unable to sleep. You often wake up because of sneezing. To prevent a sneeze without holding it in, there are a few things that need to be done.
A good first step might be removing potential allergens from your bedroom. In addition, you can do these seven tips:
Reduce pollen in the bedroom:
Close the windows, especially on high pollen days, and run an air purifier.
Keep the bed clean:
Experts recommend washing the sheets once a week and pillowcases every two days in the hottest water. Or you might consider using an allergy barrier bed cover to reduce your exposure to allergens emanating from your mattress.
Do not let pets into bed:
Pet dander in bed can cause nasal irritation and sneezing. If you really like having pets in your bedroom at night, try setting up a separate bed for your cat or dog.
Keep the Bed Clean
Keep the bedroom clean:
Vacuuming, dusting, and cleaning surfaces in your bedroom once or twice a week can help reduce dust and dander that can trigger sneezing.
Try showering at night:
A quick rinse before bed can help remove dust and pollen from the skin and may even promote a better sleep.
Check for mold in the home:
Evaluate your home for mold by visually inspecting dark, damp areas and noticing musty odors. If you think you have a mold problem, thoroughly clean the area with mildew and then use a dehumidifier.
"If the tips above don't help and you still wake up frequently to sneeze, try contacting an allergist or immunologist to learn more about your treatment options, which may include medication or allergy shots," Hong says.