Pope Francis is "responding to therapy" for double pneumonia at a hospital in Rome but it not "not out of danger," the Vatican said Saturday.

What does Pope Francis having "double pneumonia" mean? What should you look for in the elderly? How can you avoid getting pneumonia?

LONDON — Vatican officials said late Tuesday that Pope Francis had developed pneumonia in both lungs, further complicating the pontiff’s recovery. The 88-year-old pope was hospitalized Friday after a weeklong bout of bronchitis worsened. On Monday, doctors said he had developed a mix of infections in his respiratory tract.