\"America\'s Got Talent\" host Nick Cannon says he has been diagnosed with an autoimmune disease, lupus nephritis. In an interview with Piers Morgan on CNN, Cannon said he got sick most recently after hosting a Super Bowl pregame show, probably as a result of working too hard. He turned out to have two blood clots in his lungs and an enlarged heart, damage caused by the kidney problems brought on by lupus. \"I never got to that stage where I was like, \'OK, this is it,\' but I knew the severity of the situation,\" Cannon said. His wife, pop star Mariah Carey, has been his prop, Cannon said, taking care of him and their twin girls, who celebrate their first birthday next month. He told Morgan he sometimes calls her \"Dr. Carey.\" \"She is such a pro,\" Cannon said. \"She knows all the home remedies.\" Cannon, 31, is a triple threat who has acted in movies, hosted on television and had successful rap songs.