Vatican City, Holy See — Pope Francis remains in "critical" condition at Rome's Gemelli hospital. The 88-year-old, who has led the Catholic Church since 2013, is being treated for pneumonia in both lungs.

Here is what we know about his health. 

Double pneumonia

Francis was admitted to hospital on 14 February, initially for bronchitis, after appearing weak for several days and complaining of shortness of breath.  

The Vatican later said he was suffering from a "polymicrobial respiratory infection," before revealing on 18 February that he had pneumonia affecting both lungs -- part of what it called a "complex" clinical picture. 

His condition deteriorated on Saturday, with a "prolonged asthmatic attack" which required him to receive "high-flow" oxygen via nasal cannulas. 

Francis also required blood transfusions on Saturday due to a low platelet count, while on Sunday the Vatican said doctors had detected a mild renal insufficiency, which it later said was not cause for concern.

On Monday, the pope's condition showed a "slight improvement", although doctors declined to offer a prognosis, the Vatican said. 

Work continues

Despite his condition, the pope has been "in a good mood", eating normally and "not in pain", according to a Vatican source, who said he was getting up and moving between his bed and an armchair. 

From his special papal suite on the 10th floor of the Gemelli hospital, Francis has received his closest collaborators and has continued to work, while catching up with correspondence and newspapers. 

He has been reading and signing documents, notably appointments of bishops around the world, as well as making telephone calls, according to the source. 

On Monday the Vatican said Francis had called the parish of Gaza, as he has tried to do each evening since the beginning of the war.

He also met with Vatican Secretary of State Pietro Parolin, as the pope signed off on the canonization of two new saints.

Well-oiled communication

The Vatican has been providing updates on the pope's health twice a day, in a notable shift towards transparency compared to previous papacies.

Doctors said Francis himself had requested they be frank about his medical state.

Every morning around 0700 GMT, a brief statement generally indicates that the pope slept well, while in the early evening around 1800 GMT, a more detailed medical bulletin provides updates on his clinical progress.

Longest hospital stay

The 12 days Francis has spent at Gemelli so far mark his fourth and longest stay in hospital since becoming pope in 2013.

In 2021, he spent 10 days at the Gemelli for colon surgery. In March 2023, he was an inpatient for three days for bronchitis and returned in June for a hernia operation, spending 10 days in hospital. 

Susceptible

The pope, whose birth name is Jorge Bergoglio, maintains a packed schedule at the Vatican despite his advanced age and warnings from his doctors.

Not a fan of holidays, the pope has not slowed down despite knee and hip pain that has forced him to use a wheelchair since 2022.

As a young man, he had part of his right lung removed, making him more susceptible to respiratory infections.

He underwent cataract surgery in 2019 and recently began wearing a hearing aid. 

(Source: Clément MELKI, AFP)