Credit: Gary Gershoff/

Nick Cannon needs to step down.

Effectively immediately, the star, 31, has quit his daily 92.3 NOW radio show "Rollin' with Nick Cannon" after two years citing health concerns. Mariah Carey's husband (they welcomed twins Moroccan and Monroe last April) was hospitalized with kidney failure over the holidays, and was hospitalized just this past weekend when doctors discovered two blood clots in his lungs.

"Under doctor's orders, I have been asked to put my health first and cut back on some of my professional commitments in order to allow my body to get the rest that it needs to keep up with the demands of my multi-tasking schedule...even Superman needs to sleep." Cannon said in a statement, thanks CBS Radio and 92.3 NOW for "their unwavering support."

The Washington Post reports that Cannon's health took a more serious turn last Friday, when back pain sent him back to the hospital; doctors discovered not just a blood clot but an enlarged ventricle in his heart. He will continue to host his weekly syndicated show, Cannon's Countdown.