Pope Francis remains in critical condition, according to the Vatican, with blood tests showing mild signs of kidney failure “which is currently under control,” the Vatican said Sunday, as the 88-year-old pontiff battles pneumonia in both his lungs.

The pontiff's condition is touch-and-go, given his age, fragility and pre-existing lung disease, according to doctors.

ROME -- Pope Francis was resting Monday morning after a quiet night, on the 10th day of his hospitalization for a complex lung infection that has provoked the early stages of kidney failure, the Vatican said. The one-line statement didn’t say if Francis, 88, had woken up. “The night passed well, the pope slept and is resting,” it said.