Pope Francis left hospital and returned to the Vatican on Saturday after being treated for bronchitis, making light of his illness by saying: "I'm still alive you know".

The pope, 86, was taken to Rome's Gemelli hospital on Wednesday after complaining of breathing difficulties, but responded rapidly to an infusion of antibiotics, his medical team has said.

Looking to show he was fully recovered, Francis got out of his car before leaving left the hospital grounds, using a walking stick to support himself.

He greeted well wishers and talked briefly to waiting reporters, confirming that he would preside over the Palm Sunday service in St. Peter's Square and give his usual weekly address to the faithful.

Sunday's service kicks off a week of Easter events and the Vatican subsequently said the pontiff would take part in those celebrations, supported by cardinals.

Before getting back into the car, Francis embraced a sobbing mother, whose young daughter had died overnight in the hospital, and then prayed with both the parents.

He also signed the plaster cast of a young boy with a broken arm and waved from the window of his car as he drove away.

Asked by reporters if he had been afraid during his hospital stay, the pope said: "No, afraid no."

"In a hospital there is a lot of heroism, lots of tenderness for patients. You know sick people, we are capricious. Capriciousness comes with illness. You need to be patient," he said, praising the work of all the staff at the Gemelli.

"I went to the children's ward and saw with what tenderness they took care of the children," he said.

"Now I need to sleep for four days," he joked after answering the various questions.

The pope, who marked the 10th anniversary of his pontificate in March, has suffered a number of ailments in recent years.

He was last hospitalised in 2021 for surgery on his colon, but on that occasion he was hidden from view as he left the Gemelli.

He faces a testing week as the Roman Catholic Church builds up to the most important date in its calendar -- Easter Sunday on April 9 -- with a series of ceremonies, services and processions.

The dean of the college of cardinals, Giovanni Battista Re, has already said that a cardinal would help the pope during the week's celebrations and take care of altar duties.

A similar arrangement was put in place last year, when the pope sat to one side during some Easter events due to persistent knee pain, leaving it to senior cardinals to lead the Masses.