Isaak Lasson from Utah had been experiencing mild breathing problems for the past three years, but doctors were initially unable to identify the problem.
Then last week, a new medic spotted something unusual lurking in one of little Isaak's nostrils. On closer inspection, this proved to be a fungus-encased Lego wheel. (A word to the wise: try not to focus on that image for too long.)
"We think he bent it in half - it's pretty flexible - and that it opened up once it got into his sinuses," Isaak's concerned dad Craig told reporters.
Anyway, all's well that ends well - because, according to Craig, Isaak is now eating and sleeping better than he has done in ages. And Isaak's probably just chuffed that he can finally put the finishing touch to his Lego truck model...