In this post-COVID world, sneezing in public has become a bit taboo, which is a problem for those who feel a frequent tickle in their nose during the spring allergy season.
University of Wollongong medical scientist, Associate Professor Theresa Larkin says there are numerous tricks you can use to stop a sneeze if it comes along at the wrong time - but warns that holding it in once it's started can have risks.
With a sneeze designed to blast out irritants, it involves an increase of pressure in your airways so that whatever is inside can be ejected.
Prof Larkin said the pressure inside the airways during a sneeze was more than 30 times greater than heavy breathing during exercise - so keeping that pressure inside can be dangerous.
The first stage of a sneeze is a reflex that causes you to take a deep inhale, she said.
"What happens then is, for a moment, your throat closes over... and that increases the pressure in the airways and then the out breath is where you have the contraction of all your respiratory muscles and you can exhale the air," she said.
"Because that pressure is so high, if you close your mouth and nose, then the pressure inside your airwaves is 20 times even higher than a normal sneeze.
"If you don't allow that to escape through your nose and mouth, it can stay internally, and that's when then it can damage your eyes or your ears or a blood vessel inside your head.
"Injuries are quite rate - but it can happen."
With hayfever season in full-flight as trees, flowers and grasses bloom, Prof Larkin co-penned an article in the Conversation detailing the ins and outs of sneezing.
If you want to stop one from happening when you first feel a tickle, Prof Larkin said you can try pulling your ear, putting your tongue to the roof of your mouth or the back of your teeth, touching your nose, or sticking your finger in your nose.
"It's okay to stop a sneeze from starting, but once it started you probably shouldn't stop it by fully closing your mouth and nose," she said.
"You could still quieten it down by, for example, holding your mouth but letting it come through your nose or vice versa, but once a sneeze is actually going and you've done the big inhale that's when it's not good to stop it because the pressure has already built up."
She said the reason these sneeze-stopping tricks work is due to the body's "gate control mechanism", which is also why rubbing an injured area when you kick your toe or slam your finger in the door can reduce the sensation of pain.
"We can override incoming pain signals by the stimulus of touch or pressure, and that's because at the spinal cord, we've got what's called this gate control mechanism," she said.
"When there's a pain nerve stimulated, its signal travels through to the spinal cord and essentially the gate is opened via interconnecting neurons which means the message will continue up to the brain and it feels pain.
"But when we apply pressure, then the nerve with the physical touch signal is bigger and it sort of has more priority at the level of the spinal cord and it blocks the signal from going up to the brain."
If you're happy to let your sneezes just take their course, Prof Larkin says you should "embrace your personal sneeze style" and try to use a tissue, with sneezes travelling at about five metres per second.
"Sometimes people don't want to sneeze, if it's not the right time, if it's going to be embarrassing or if you don't have a tissue," she said. b
"But we should let it happen because if we've got an irritation in our nasal cavity and we leave it there, then it could cause some actual irritation to the mucosa," she said.
Kate McIlwain
For more than a decade, I've helped the Illawarra Mercury set the news agenda across the region. Currently I'm the paper's health reporter - covering the stories of Illawarra workers and residents in the wake of a global pandemic and at a time where our health systems are stretched to the limit.
For more than a decade, I've helped the Illawarra Mercury set the news agenda across the region. Currently I'm the paper's health reporter - covering the stories of Illawarra workers and residents in the wake of a global pandemic and at a time where our health systems are stretched to the limit.
