Pope Francis did not receive anyone in audiences on Friday because he has a fever, the Vatican said on Friday.
Vatican spokesman Matteo Bruni did not provide any further details on the health of the 86-year-old Roman Catholic leader.
"Because of a fever, Pope Francis did not receive (anyone) in audiences this morning," Bruni said in response to a reporter's question on why none were listed on his daily schedule earlier in the day.
Francis spent five days in a Rome hospital at the end of March for bronchitis but recovered quickly following an infusion of antibiotics and returned to his duties, including a three-day trip to Hungary at the end of April.
He appeared to be fatigued at a meeting with students near the Vatican on Thursday afternoon.
Francis, who became pope 10 years ago, is missing part of one lung. It was removed when he was a young man in his native Argentina.
Since he assumed the papacy, he has had to cancel events, sometimes at the last minute, because of fevers.
He was first hospitalised as pope in 2021 for an operation to remove part of his colon.
None of the pope's scheduled events have been cancelled. He is due to preside at a Mass marking Pentecost on Sunday in St. Peter's Square and receive Italian President Sergio Mattarella on Monday.
It was not clear if he would hold private audiences on Saturday.
The Vatican announced earlier this week that the pope was expected to travel to Portugal from Aug. 2-6 to attend the World Youth Day and visit the Shrine of Fatima.
(Reporting by Philip Pullella; Editing by Hugh Lawson and Frances Kerry)
