Pope Francis had reportedly been complaining of breathing difficulties.
Pope Francis has "progressively improved" after spending the night in the hospital with a respiratory infection, the Vatican Press Office said Thursday.
The pontiff rested well during the night, Matteo Bruni, director of the Press Office of the Holy See, said in a statement issued in Italian.
"The clinical picture is progressively improving, and the planned treatments continue," Bruni said, according to a translation. "This morning after having breakfast, he read some newspapers and went back to work. Before lunch he went to the little chapel of the private apartment, where he gathered in prayer and received the Eucharist."
Francis, 86, was taken on Wednesday to the Gemelli University Hospital in Rome. Officials said he would be required to stay for several days to receive "appropriate medical treatment."
Pope Francis attends the weekly general audience in St. Peter's Square at the Vatican, March 29, 2023.
Guglielmo Mangiapane/Reuters
"In recent days, Pope Francis complained of some respiratory difficulties and this afternoon he went to the Gemelli [hospital] for some medical checks," a statement released on Wednesday read. "The outcome of these showed a respiratory infection (excluding Covid 19 infection) that will require several days of appropriate hospital medical treatment."
It is unknown what type of respiratory infection the pope has or what type of care he will need.
The overnight stay marked the first time the Vatican has publicly announced that Francis has gone to the hospital since he underwent surgery to have part of his colon removed in July 2021.
A nun stands in front of St. Peter's square after Pope Francis was hospitalised for a respiratory infection, at the Vatican March 30, 2023.
Yara Nardi/Reuters
President Joe Biden mentioned the pope during remarks at an event Wednesday celebrating Greek Independence Day.
"The pope is ill now, so say an extra prayer for him," said Biden, who in 2021 became the first Roman Catholic U.S. leader in more than half a century to meet at the Vatican with the head of the Catholic Church.
Francis on Thursday sent a message of thanks to those who'd wished him well.
"I am touched by the many messages received in these hours and I express my gratitude for the closeness and prayer," he said on Twitter.
ABC News' Joe Simonetti contributed to this report.