Science explains why random things like looking at bright lights can make you sneeze



is set off by many different things.

Franklin / Flickr

Aside from allergies, you can sneeze at seemingly random
things. I sneeze every time I start chewing a piece of gum.

It happens to other people whenever they look at a bright light or toward the sun, or
even when they pluck their eyebrows or have sex

So why does this happen?

It turns out that sneezes start in your nerves. They are one of
your body’s ways of keeping out irritants in your nose and
throat, according to a
post on the blog Penn Medicine News
, which is
maintained by the University of Pennsylvania.

“It’s a nerve transmission that tells your brain something is in
your nose that needs to come out,” Dr Neil Kao, an
allergy and asthma specialist at the Allergic Disease and Asthma
Center in Greenville, South Carolina
told WebMD.

When something enters your nose, it sets off the “sneeze
sensor” in your brain, which then sends signals for you to
to close your throat, eyes. and mouth. Next, your chest muscles
contract and your throat muscles relax. This forces air
(along with anything else) out of your mouth and nose. That’s a

However, our noses don’t always get it right, and sometimes our
body mistakes harmless things as an attack. 

Strange sneeze triggers:

  • Plucking your eyebrows is a common culprit.
    Dr. Melanie
    , an assistant clinical professor of
    dermatology at Columbia University,
    told New York Magazine’s The Cut
    that tweezing may set
    off the trigeminal
     which passes sensations between
    the brain and the face.
  • Exercise can set some people off on a sneeze
    spree. You hyperventilate when you’re
    , which means your nose and mouth start to
    dry up. Your nose compensates for this by drippings, which
    triggers a sneeze.
  • Bright sunlight causes sneezing for a third of people.  This light
    sensitivity is an inherited trait and is known as the “photic
    sneeze reflex.” There’s no hard evidence for why it happens,
    but some research suggests that the
    reflex that makes your pupils dilate and the reflex that makes
    you sneeze are connected in light-sensitive people. 
  • Sex may make some people sneeze too.
    A 2008 review in the Journal of the Royal Society of
    Medicine called
    it an “underreported phenomenon.”
    think that the stimulation of the parasympathetic nervous
    system — part of the nervous system responsible for
    the stimulation of “rest-and-digest” or “feed and breed”
    activities — fires off signals that makes people sneeze either
    when they’re thinking about or orgasming from sex.
  • Alcohol. Some people sneeze after
    drinking alcohol, as well as other nasal symptoms. Doctors
    think this is probably because blood vessels in the nose
    dilate, resulting in mucus production, known as a form of
    non-allergic rhinitis.
  • Chewing gum. I can’t find a definitive answer
    for this one, but it seems to affect a fair few people. One
    answer I’ve got is that the vapour given off by minty flavours
    is very powerful, and this tickles the inside of your nose,
    triggering a sneeze.

from SAI