Pope Francis appears to have an "early, mild renal insufficiency" as he remains hospitalized in critical condition, the Holy See Press Office said in Sunday evening update.

Though some blood tests showed "initial, mild, kidney failure," doctors said it was under control. "The complexity of the clinical picture, and the necessary wait for drug therapies to provide some feedback,

Pope Francis rested overnight in the hospital, the Vatican said earlier Sunday, adding that his night "passed peacefully."