Credit: Jeff Kravitz/FilmMagic

Kidney failure. Two blood clots in his lung. Nick Cannon has endured some very serious health setbacks in the past couple months, which makes his recent decision to end his daily radio show understandable.

And now, the 31-year-old husband to Mariah Carey and father to her twins Moroccan and Monroe, 10 months, reveals to Us Weekly that his medical woes all stem from an "autoimmune disease . . . like a lupus type of thing, but no one else in my family has it."

"It's a lot of stuff," Cannon told Us, "but it's all in order now . . . I feel blessed to be alive."

And Cannon was by his wife's side Thursday night for another happy occasion: Her first performance since giving birth to the twins back in April 2010.

"Do you love them babies?" she asked the crowd, dedicating "Always Be My Baby" to "Roc" and "Roe." "Cause I do!"