Sighing isn't a sign of boredom -- it's crucial to human health

Californian scientists have identified the source of the sigh. It is not just a response to sadness, depression or despair: it is, also, they report, a life-sustaining reflex that helps preserve lung function.

And a control system in the brain keeps humans sighing about a dozen times an hour, even when they aren’t thinking about the future of the NHS, the European referendum or the latest pronouncements of Donald Trump.

Researchers report in Nature that two tiny clusters of nerve cells in the brain’s stem – the region that, unbidden, automatically takes charge of breathing, sleeping and heart rate – orchestrate the sigh. They do this in a response to an unconscious command to reinflate as necessary the myriad tiny sacs in the lungs called alveoli, which control the body’s traffic in oxygen and carbon dioxide, and which sometimes collapse.

“Unlike a pacemaker that regulates only how fast we breathe, the brain’s breathing centre also controls the type of breath we take,” said Mark Krasnow, a biochemist at the Stanford University School of Medicine, and one of the authors.

Lord Foul wrote:I do a lot of that...especially whilst on here.....generally the sort related to despair

Raggamuffin wrote:I think sighing is more a sign of irritation than anything else.