It's a bad idea to hold your nose and keep your mouth closed when you sneeze, scientists from the University Hospitals of Leicester NHS Trust have warned.

A man is his thirties was recently admitted into a hospital after blocking his nose during a "forceful" sneeze. What followed were hours of considerable pain, write doctors Wanding Yang, Raguwinder Sahota and Sudip Das in the journal BMJ Case Reports.

All the patient had tried to do was to contain his sneeze. It was immediately followed by a "popping" sound and his neck began to swell. It turned out he had perforated his pyriform sinus – a pear-shaped sinus located on either side of the larynx, rupturing the back of his throat in the process.

A few hours after arriving at the hospital for examination, he was in excruciating pain, couldn't swallow and was unable to talk.

While examining him, doctors could hear popping and cracking sounds – called "crepitus" – that extended from his neck to his ribcage. It suggested that air bubbles were located in the deep tissue and muscles of his chest. This was confirmed with an emergency computed tomography (CT).

Rupturing the back of a throat is a rare condition that usually comes from a specific trauma, surgery or infection. If it's not caught and treated early on, it can lead to serious complications. Doctors of the University Hospitals of Leicester's ENT, Head and Neck Surgery Unit were surprised to come across a case whose cause was unknown.

The man risked serious complications such as neck infection and was admitted to the hospital immediately after the diagnosis was complete. He had to be fed by tube (through the nose) and given intravenous antibiotics until the swelling and the pain had decreased.

It took him a week to recover and he was finally discharged on the advice of never trying to block his nose while sneezing again.

Doctors are now warning people against the apparently innocent but extremely dangerous practice.

"Halting sneezing via blocking [the] nostrils and mouth is a dangerous manoeuvre, and should be avoided," they say.

They point out that blocking one's nostrils and mouth can lead to even more painful conditions.

"It may lead to numerous complications, such as pseudomediastinum [air trapped in the chest between both lungs], perforation of the tympanic membrane [perforated eardrum], and even rupture of a cerebral aneurysm [ballooning blood vessel in the brain]," they explain.