It's said to be "exceedingly rare," but a study in the BMJ Case Reports journal documents the case of a 34-year-old UK man who showed up at a Leicester hospital complaining he was having a hard time swallowing, and that he felt a "popping sensation" in his neck. After some prodding, doctors discovered the man had suppressed a sneeze by pinching his nose and clamping his mouth shut. That ended up rupturing his throat from the force of the stifled sneeze, rendering him voiceless and landing him in the hospital. Anthony Aymat, a London doctor not involved in the study, explains to the AP that sneezes can escape your body at 150mph or so, and that if you try to keep one inside, "it could do a lot of damage and you could end up like the Michelin Man with air trapped in your body."
Although they say a throat rupture like this is rare, the study's researchers elaborate on other potential complications, including a brain aneurysm or eardrum damage, per the Guardian. The University of Texas' Dr. Zi Yang Jiang, who says he sees a couple of sneeze-induced issues each year, tells the AP a collapsed lung is also possible. Doctors used scans to assess this patient and found the popping sound was caused by air bubbles that had formed in his throat tissue and neck. "The whole point of sneezing is to get something out of your body, like viruses and bacteria ... if you stop that, those may end up in the wrong part of the body," Jiang says. The patient was given antibiotics, fed through a tube, and released a week later, with strict instructions to let future sneezes fly. "The safest thing to do—although it's not socially acceptable—is just to sneeze loud," Aymat tells the AP. (Allowing yourself a hearty sneeze could also dislodge the toys stuffed up your nose for decades.)