The Vatican issue major health update on Pope Francis after being left in critical condition following 'respiratory crisis'

The Vatican has issued an update on the health of the Pope, who fell into a critical condition last week.

Pope Francis was diagnosed with pneumonia in both of his lungs following his admission to Rome's Gemelli Hospital on February 14 with chronic bronchitis, which is a respiratory infection.

According to Cleveland Clinic, pneumonia is 'inflammation and fluid in your lungs caused by a bacterial, viral or fungal infection. It makes it difficult to breathe and can cause a fever and cough with yellow, green or bloody mucus'.

It also indicates that pneumonia can be life-threatening 'if left untreated, especially if you have an underlying health condition'.

The 88-year-old is understood to have had a restful tenth night in hospital, according to a statement issued by the Vatican.

"The night went well; the Pope slept and is resting," read the statement.

It comes as officials close to the Pope explained how he was in a 'critical' condition just yesterday evening (February 23), while also adding that he hasn't suffered any 'further respiratory crises' since Saturday morning (February 22).

Pope Francis even managed to attend Mass in his apartment in the hospital, accompanied by doctors and nurses overseeing his treatment.

Pope Francis greeting a crowd from the Vatican balcony (ALBERTO PIZZOLI/AFP via Getty Images)

While yesterday's statement from the Vatican also noted that he had received blood transfusions which were aimed at raising his hemoglobin levels.

It read: "The thrombocytopenia remains stable; however, some blood tests show early, mild renal insufficiency, which is currently under control.

"High-flow oxygen therapy continues through nasal cannulas."

Two people allegedly clued-up on the situation told Politico just days ago that the leader of the Catholic Church has been 'suffering from intense pain and has privately expressed certainty he won’t make it this time'.

While a third person is understood to have told the US-based publication that Francis - who was born in the Flores neighborhood of Buenos Aires, Argentina - is acting entirely on 'doctor's orders'.