host Alex Trebek is taking a medical leave after undergoing surgery to remove blood clots from his brain, Trebek and his production team said Thursday. Trebek, 77, was diagnosed in mid-December with a condition known as subdural hematoma, a complication from hitting his head in a bad fall in October, he said. "After two days in the hospital, I came home to start recovery," Trebek said in a video posted to the game show's website.