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

The slight renal insufficiency the pope had in recent days subsided and a CAT scan of the chest showed a normal evolution of the pulmonary inflammatory picture.

The combination of health issues has kept the Pope from performing his public duties, including weekly prayers on Sundays, but his doctors have recently said he is alert, joking, and continuing to work, as well as reading messages from well-wishers around the world.