Sneezing is a natural defence against things that irritate the nasal membrane.  Nerve signals get the muscles of the chest and throat to respond, expelling mucous out of the mouth and nose.

According to researchers, it is not just germs and pollen that can cause a sneezing attack.  Bright light, including sunlight, can bring on a fit of sneezing.  German researchers at Saarland University Medical Centre found most of more than 1,000 patients they interviewed in their ear, nose and throat department had experienced photic (caused by light) sneeze reflex ‒ funnily named ACHOO (Autosomal Compelling Helio-Ophthalmic Outburst).  It is estimated that 18 to 35 per cent of the population sneezes when exposed to sudden bright light.

Humans do not sneeze in their sleep. Some researchers believe sneezing may not happen during rapid eye movement (REM) sleep ‒ in which dreams occur. That is because the body’s muscles relax and reflex reactions shut down.

A sneezing fit may go on for years. According to the Guinness World Records, the longest sneezing fit currently stands at 976 days.  Briton Donna Griffiths started sneezing on the 13th of January 1981 and surpassed the previous duration record on July 26, 1981.  She sneezed an estimated million times in the first 365 days and achieved her first sneeze-free day on September 16, 1983.  That is a lot of tissues!