World has watched Pope's health decline

During his long papacy, the world has followed the ups and downs of Pope John Paul's health as if he were a universal grandfather.

Elected in 1978, the Pope has gone from robust globetrotter to a frail, pained man weighed down by Parkinson's disease and arthritis and confined much of the time to a wheelchair.

On Thursday the Vatican released news of a urinary tract infection and high fever to add to the breathing difficulties and other complications that forced doctors to admit him to hospital in February. He was already breathing through a hole cut into his throat and being fed through a tube in his nose.

In 1981, only three years after being elected, Karol Wojtyla survived an assassination attempt that left him with a large part of his intestines destroyed, but he bounced back quickly.

By the 1990s, though, his various ills visibly took their toll and Catholics began to fear the Holy Father could die soon. But he struggled on, putting his suffering on public display as a silent sermon on the dignity of every person, well or ill.

In recent years, aides have convinced him to limit his activities, and he has often presided at major Masses sitting on the sidelines while a stand-in celebrated them for him.

In 2003, arthritis made it virtually impossible for him to stand or walk without intense pain. Not even a cane could help. Vatican technicians devised a wheeled throne which they could raise to allow the Pope to say Mass while seated.

It was a huge change for the once-avid skier and hiker who used to leave much younger aides breathless.

John Paul's papacy is the most public in history and the world has watched him age. The presence of television cameras at all his public appearances often magnifies his declining health.

In recent years, his left hand has trembled uncontrollably. His ruddy, chiselled Slavic face has given way to a puffiness and stiffness caused by Parkinson's and the medicines used to control it.

The Pope alarmed the world in September 2003 when he looked particularly weak during a four-day trip to Slovakia and aides had to help him finish his speeches.

He looked exceptionally frail the next month at ceremonies for the 25th anniversary of his papacy, but rested in the months that followed and again enjoyed relatively good health in 2004.

But in February this year, the Pope was rushed to Rome's Gemelli hospital twice with breathing problems, undergoing a tracheotomy on his second visit that left him unable in two separate attempts to pronounce a blessing for the faithful.

His failing health has inevitably led to questions about whether he should retire voluntarily, something no Pope has done since Celestine V in 1294. But John Paul has said he is determined to see to the end the mission that God has given him.

Catholics are divided. Some saying his illness blocks the Church's business while others see in his very public struggle an inspiration to a world where old people are increasingly put away in homes and forgotten. Before his health began to decline noticeably in the 1990s, the Pope's ability to recover from accidents and illnesses for most of his life was attributed to his love of physical activity as a young man, priest and bishop.

Karol Wojtyla's first medical emergency as Pope occurred three years after his election. On May 13, 1981, Turkish gunman Mehmet Ali Agca shot him during an audience in St Peter's Square.

He nearly died from wounds to the stomach and hand. The bullets came within a hair's breadth of hitting vital organs.

Doctors operating furiously for five hours saved his life in emergency surgery in the Catholic Gemelli hospital.

He was released from hospital less than two weeks later but had to return for treatment of a virus infection contracted by blood transfusions during the first surgery and to have a temporary colostomy.

History's most travelled Pope, he was back on the road nine months later with a gruelling trip to four African countries.

For the next decade he enjoyed near-perfect health.

In July 1992, when he was 72, the Pope entered hospital for the removal of a large intestinal tumour the size of an orange. The tumour was caught as it was beginning to turn malignant.

During that operation doctors also removed his gall bladder when they found it to contain many stones. Lymph nodes were also removed in case the tumour had already started to spread.

His personal doctor, Renato Buzzonetti, came under intense media criticism for not having detected the tumour earlier. But the Vatican said the Pope had not shown any symptoms until several weeks before the operation.

It was the start of a spate of health problems. In 1993, the symptoms of Parkinson's disease began to appear.

The Pope's left hand began to tremble. His facial muscles appeared stiff, leading to the mask-like expression so familiar with the disease - a disorder of the central nervous system.

In 1993, after falling down the stairs of his throne and dislocating his right shoulder, he blessed the faithful with his left hand and joked about a report that he was suffering from amnesia and fainting spells, a report the Vatican denied.

"The Pope salutes you," he once said. "It's a slightly deficient Pope, but still in one piece and not dead yet."

In 1995, the world was alarmed when influenza forced the Pontiff to miss Christmas Mass for the first time. Later, nausea forced him to interrupt a televised Christmas address.

In 1996, he twice had to cancel engagements because of a fever which the Vatican said was of a "digestive nature".

The Vatican said later that all three episodes were caused by a recurring inflammation of the appendix. The discrepancies in official versions left some reporters sceptical.

John Paul later had his appendix removed.

On the eve of the millennium year, 2000, the Vatican quietly scaled down plans for him to make an appearance every day of the year. He still faced a busy programme, but passed with flying colours.