Stifling a sneeze can rupture your throat, burst an ear drum, or pop a blood vessel in your brain, researchers warned Tuesday.
Many people -- when they feel a sneeze coming on -- block all the exits, essentially swallowing the sneeze's explosive force.
Just how dangerous this can be was illustrated when a 34-year-old man showed up at the emergency service of a hospital in Leicester, England recently, with a swollen neck and in extreme pain.
"The patient described a popping sensation in his neck after he tried to halt a sneeze by pinching the nose and holding his mouth closed," doctors detailed in a study published in the medical journal BMJ Case Reports.
A CAT scan confirmed what they suspected: the force of the suppressed sneeze had ruptured and torn open the back of the throat.
The man -- who could barely swallow or talk -- was admitted to hospital, where he was tube-fed and given intravenous antibiotics until the swelling and pain subsided.
He was discharged after a week.
"Halting sneezing via blocking the nostrils and mouth is a dangerous manoeuvre, and should be avoided," the doctors concluded.
In rare cases, stifling a sneeze has led to a condition in which air gets trapped between the lungs, "and even rupture of a cerebral aneurysm," which is a ballooning blood vessel in the brain, they explained.