When sitting in a quiet theatre or a packed train, stifling a sneeze by holding the nose and closing the mouth may seem like the courteous option.

But doctors have warned against the polite practice, after a man ruptured the back of his throat while trying to contain the convulsive explosion of air.

The 34-year-old was admitted to hospital barely able to swallow or speak after pinching his nose and clamping shut his mouth to stop a sneeze.

When doctors examined him they also heard strange popping and crackling sounds, which extended from his neck all the way down to his ribcage.

A scan confirmed that that air from his lungs had bubbled its way into the deep tissue and muscles of the chest when it could not escape.

Ear, nose and throat specialists at the University Hospitals of Leicester NHS Trust released details of the man’s condition in BMJ Case Reports and warned that trying to contain a forceful sneeze could lead to ‘numerous complications’ and even a lethal brain aneurysm.