Concerns over Pope Francis' health have mounted in recent years as have questions about his succession. Here's what we know.

Pope Francis, who is in critical condition with a complex lung infection, offered his thanks for the "many messages of affection" he has received since he was hospitalized earlier this month. "I have been particularly struck by the letters and drawings from children,

Pope Francis is in stable condition after his episodes of acute respiratory failure on Monday, the Vatican said Tuesday.