Pope Francis, The First One-Lunged Pope

When white smoke billowed over Vatican City and Jorge Mario Bergoglio donned the white robes and addressed the world for the first time as Pope Francis, he became the first pope from the Americas. He also became the first pope missing part of his lungs.

Pope Francis, who reportedly had part of a lung removed at age 21 because of an illness, is not expected to be restrained in any way because of his missing organ.

He's had several decades to adjust to this and his other lung has taken over," said Blair Marshall, chief of thoracic surgery at MedStar Georgetown University Hospital in Washington, according to a report by Bloomberg News. "He's been functioning well for decades and should have no limitations. The only risk would be if he gets pneumonia."

Pope Francis, 76, should not face any travel restrictions and have any difficulties preforming the high-stress role as the spiritual leader of the world's 1.2 billion Roman Catholics, Marshall said.

It is unclear exactly why Pope Francis had to have lung tissue removed though Marshall speculated it may have been due to tuberculosis or necrotizing pneumonia, wherein bacteria destroys lung tissue.

While lung infections are no longer treated with surgery, it was often common practice in the mid-1950s when widespread access to antibiotics was not available, the Bloomberg report stated.

"It was probably a pretty bad infection, and maybe even an abscess, that might have caused him to bleed," said John Belperio, association professor of pulmonary and critical care medicine at the David Geffen School of Medicine at University of California Los Angeles, according to TIME. "If he were bleeding a lot in the lung, the only thing to do is to resect the lung, take it out, to stop the bleeding."

Other possibilities for the lung's removal include addressing a birth defect which caused abnormality in the lung tissue, or an unusual growth of blood vessels in the air sacs that would obstruct breathing, the TIME report stated.

Since the pope has now lived most of his life without both lungs intact, no problems are expected.

"A whole lot of people get a portion of their lung removed and do just fine," said Sumita Khatri, a pulmonologist and co-director of the Cleveland Clinic Asthma Center in Ohio, according to the Bloomberg report. "His experience for the past 50 years more than tell us that he has lung enough for the job."