Dar es Salaam, Feb. 20 -- VATICAN: POPE Francis has been in hospital for more than a week with what some media reports are now calling “double pneumonia”.

The Vatican released a statement on Tuesday evening saying, “laboratory tests, chest X-rays, and the clinical condition of the Holy Father continue to present a complex picture.”

The 88-year-old Catholic leader has a long history of respiratory illness. So, what makes this bout of pneumonia – a severe lung infection – so “complex”? And how will it be treated?

What is double pneumonia?

Pneumonia is a serious infection that fills the lungs with liquid or pus and can make it difficult to breathe. People may also have chest pain, cough up ...