Pope Francis, at age 76 only two years younger than his predecessor Benedict XVI upon his election, enjoys good health, the Vatican said Thursday while confirming that he had part of his lung removed as a boy.
"Many, many years ago he had an operation in which part of a lung was removed," Vatican spokesman Federico Lombardi told reporters the day after Francis's historic election.
"Those who know him have always seen him in good health," Lombardi said, adding: "This is not a handicap in his life."
A 2010 biography revealed that the young Jorge Mario Bergoglio had the operation after suffering from pneumonia and took months to recover.
In the book, the then Buenos Aires archbishop is quoted as saying: "I remember the moment when, with a raging fever, I hugged my mother and said: 'Tell me what is happening!' She didn't know what to say, because the doctors were perplexed."
As a young man Bergoglio wanted to work as a missionary in Japan but was turned down because of his health, one of the authors, Francesca Ambrogetti, wrote in "The Jesuit".
The former Jesuit priest is particularly reserved about his health, Ambrogetti noted.
Francis -- who walks with a limp -- is known at home for using public transport and riding a bicycle.
His election came about because of Benedict's shock resignation last month citing failing physical and mental faculties after nearly eight years as pope.
Observers said the historic decision would set a precedent for future popes and brought to mind the long and highly public decline of Benedict's predecessor John Paul II.
The Polish pope, a sprightly 58 when he was elected in 1978, died aged 84 ravaged by Parkinson's disease.
Rather than considering retiring, John Paul II chose to soldier on, turning his visible personal suffering into a way of sharing that of millions of others -- a metaphor for bearing the cross.
For his part, Francis said he realised the spiritual significance of pain when the nun who had prepared him for his first communion came to visit him in hospital after his lung operation, according to "The Jesuit".
"She said something which left a big impression on me and brought me great peace. She said: 'You are imitating Jesus'," he told Ambrogetti.
"Pain is not a virtue in itself, but the way we live with it can be virtuous. It makes us human" and helps us recognise Christ's humanity, he said.
According to Argentina's La Nacion daily, in 2007 Bergoglio suffered an inflammation of the sciatic nerve that prevented him from travelling to Rome to take part in a consistory convened by Benedict.