Written by Tom Clarke, a Science and technology editor

As we age, our ability to fight off infections or ailments that wouldn’t have troubled us before gradually diminishes.

Pope Francis is 88 and unlike many people lucky enough to live that long, has a demanding job that likely leaves less time for the rest that our bodies, especially ageing ones, need.

The latest update from the Vatican suggests he isn’t gravely ill – able to sit up and eat breakfast – but that his doctors have concluded the bronchitis he is suffering will require a longer hospital stay.

Bronchitis – an inflammation of the main airways leading to the lungs – can be severe as it can narrow those pipes leading to difficulty breathing.

It’s only a real concern if the infection doesn’t respond well to treatment and spreads deeper into the lungs themselves causing pneumonia.

The Vatican has said the pope’s infection is “polymicrobial” meaning more than one type of microbe (bacteria, virus or fungal agent) has been identified.

That will mean adjusting the types of medication used to treat the infection, which in some cases can be tricky, especially if one of the bugs is resistant to common antimicrobial drugs – something that is increasingly common.

The pope is possibly more vulnerable to lung infections than a person of equivalent age as he had part of one lung removed following a severe infection when he was just 21.

He was previously hospitalised in 2023 with pneumonia and made a good recovery.

Beyond that, it’s unwise for anyone to pontificate on anyone’s personal health, least of all the pontiff’s.