A UK man who tried to suppress a sneeze was so successful, he ripped a hole in the back of his throat.
Doctors are now warning against blocking your nose and closing your mouth or you may end up in considerable pain, barely able to speak or swallow.
The 34-year-old's bizarre case has been detailed in the latest issue of the journal BMJ Case Reports.
After pinching his nose to block a big sneeze, his neck swelled up, and he kept hearing popping and crackling sounds.
Doctors examined him and found air bubbles in the deep tissue and muscles around his chest, which got there through a rupture in the back of his throat.
He was rushed to hospital, where he spent the next week being fed by a tube and on intravenous antibiotics.
"Halting sneezing via blocking [the] nostrils and mouth is a dangerous manoeuvre, and should be avoided," the authors cautioned.
- Doctors warn against using coffee enemas
- Doctors warn against putting glitter in your vagina
- The strange ways Kiwis hurt themselves at Christmas
They say other possible complications include perforated eardrums and even rupture of a cerebral aneurysm, which can cause stroke.
In this case the man was lucky - he was discharged after a week, with just a warning not to block any more sneezes.