Pope Benedict XVI predicted a "short reign" in comments to cardinals just after his election, it has emerged.
Cardinal Joseph Ratzinger has had ailments in the past, including a 1991 stroke, that raise questions about how long his papacy will last.
Cardinal Cormac Murphy-O'Connor
Benedict, at 78, is the oldest pontiff elected in 275 years.
The Vatican have refused to comment on Benedict's health, citing his privacy. The Vatican never officially confirmed Pope John Paul II suffered from Parkinson's disease until after he died at age 84.
But several cardinals acknowledged that Benedict's term will be marked in years, not decades, and that he is not likely to be the globe-trotting pope that John Paul became after taking the helm of the Roman Catholic Church at age 58.
"We'll see what he feels like. I mean he's not a 56-year-old, you know," said British Cardinal Cormac Murphy-O'Connor. "He's a little bit older than that. So he may not do too much travelling. But you never know."
The Pope referred to his tenure in comments to cardinals just after his election on Tuesday, when he explained his choice of name. Pope Benedict XV, who served from 1914 to 1922, worked to prevent World War I during his brief pontificate.
Chicago Cardinal Francis George said Pope Bendedict, who had repeatedly asked John Paul to let him retire, told the cardinals, "I too hope in this short reign to be a man of peace."
Although he has no apparent history of chronic health problems, the German was hospitalised at least twice in the early 1990s, including in September 1991 after he suffered a stroke that temporarily affected his vision.
There is no indication the stroke left any lingering health difficulties.