A rainbow was spotted over the hospital room where Pope Francis, 88, is being treated for pneumonia at Rome's Gemelli hospital, in a poignant moment as he battles his health issues.

The Pope, who has privately admitted he may not survive this illness, was rushed to the hospital on Friday after experiencing significant chest pain, despite having resisted calls to leave the Vatican for days.

The sight of the rainbow, which appeared the other day, curving over the Pontiff's hospital quickly gained attention, with the powerful image of the hospital and the rainbow spreading across social media.

Pope Francis was admitted for tests and treatment for bronchitis, but the sudden appearance of the rainbow has been seen by many as a symbol of hope during this difficult time for the beloved leader of the Catholic Church.

"The laboratory tests, chest X-ray, and the Holy Father's clinical condition continue to present a complex picture," the Vatican said in a statement. While his condition is concerning, the pope remains in "good spirits."