The 88-year-old pontiff has been hospitalized for six weeks with pneumonia in both lungs. He will need to rest in the Vatican for at least two months, his doctors said.

Before leaving the hospital, the Pope gave a thumbs-up to the crowd after he was wheeled out onto the balcony.

The head of Pope Francis' medical team says there was a crisis during the pontiff's battle with pneumonia so dire, they considered "whether to stop and let him go."