Pope's health improving since hospitalization for infection, Vatican says. What we know.

Pope Francis' health was "progressively improving" Thursday after he was hospitalized following difficulty breathing in recent days, the Vatican said.

The 86-year-old pontiff's condition called into question his participation in Palm Sunday and upcoming Holy Week events.

Here's what we know about Francis' condition.

What is the pope's prognosis?

Francis, who had part of one lung removed as a young man, was hospitalized at Rome's Gemelli hospital Wednesday with a respiratory infection.

The pontiff does not have COVID-19, but he is expected to remain in the hospital for a few days of treatment, Vatican spokesman Matteo Bruni said Wednesday. His audiences were canceled through Friday.

Bruni said that Francis read the newspapers and was working from his hospital room at the Gemelli.

“Before lunch he went to the little chapel in the private apartment, where he gathered in prayer and received the Eucharist,” the statement said.

Has Pope Francis said anything about his improving health?

In a tweet, the pope on Thursday expressed thanks for prayers directed toward his health.

"I am touched by the many messages received in these hours and I express my gratitude for the closeness and prayer," he said.

When was Pope Francis last hospitalized?

Francis was last hospitalized in July 2021, when he spent 10 days at the Gemelli to have 33 centimeters (13 inches) of his colon removed.

Soon after, he said he had fully recovered and could eat normally, though earlier this year, he told the Associated Press his diverticulosis, or bulges in the intestinal wall, had “returned.”

He sometimes uses a wheelchair for knee issues but has resisted surgery to address those problems because he did not respond well to general anesthesia during the 2021 intestinal surgery.

What events are upcoming in the Catholic church?

Palm Sunday, which commemorates Jesus' entry to Jerusalem where he was greeted by people waving palm branches, is this weekend.

It wasn't immediately clear how Francis' medical condition would affect the Vatican's Holy Week observances, including Holy Thursday, Good Friday, the Easter Vigil and finally Easter Sunday on April 9.

Contributing: Associated Press

This article originally appeared on USA TODAY: Vatican: Pope's health improving after hospitalization. What we know.