Ask A Scientist© Biology Archive

Author:      t-man
Text:        I have often wondered why people hiccup.  What is the scientific 
reason behind this?  I know it comes from random muscle contractions in the 
abdomen but why is it random, and why does it occur in the first place?  Is 
there any fool-proof way to get rid of them?  I have heard that eating a 
tablespoon of pure sugar straight works, and drinking from a cup backwards, 
and many other ways.

Response #:  1 of 1
Author:      wizkid
Text:        Hiccups have baffled researchers for the longest time!  Only 
recently have we begun to form more concrete explanations for this reflex.  
Why do we hiccup?  Essentially, it is to prevent us from ingestion any food or 
drink during the hiccup session.  Hiccups are triggered by stimulation of 
nerves in upper part of the stomach and/or lower part of the esophagus.  The 
stimuli seem to be gases, such as air.  When we eat too rapidly, we often gulp 
down air along with food.  Most of it should escape back up (burping), but 
some get trapped between layers of food.  Hiccups are a way of forcing the air 
up and out of the system.  Hopefully, they will cause enough discomfort and 
embarrassment to get you to stop eating until all the air escapes.  You can 
see why drinking carbonated beverages may also start an uncomfortable round of 
hiccupping.  The time between hiccups seem to correspond to gastric movements, 
which, yes, may seem random.  However, over the long run, they do seem to have 
a more or less predictable rhythm.  The trick is to help your system for the 
trapped gasses either up or down.

UP:  Tilt head to look straight up, thus opening the airways to the maximum 
extent.  Take very deep breaths, which helps the diagram push on the stomach.

DOWN:  Drinking water does help, as long as you drink slowly and plenty.  The 
pure sugar remedy you mentioned may help to stimulate digestion.  Just do not 
ingest anything which might require chewing, since the processes introduces 
more air into the system.



Hiccups may involve a tapering effect, too, which means that the reflex 
continues for a short time after the stimuli is gone.  But the sooner your 
digestion settles, the sooner hiccups will stop.  There may also be a 
psychological part, too.  The "drinking from a cup backwards" and "shocking a 
hiccup away" may work by affecting the sympathetic nervous system, essentially 
"resetting" the nerves.  Some GI injuries may cause chronic hiccupping.  
Chemical burns (too much hot peppers), infections, ulcers, etc.  may cause 
such injuries.  Some people simply cannot stop hiccupping for days!  But for 
most of us, prevention is better than cure:  eat slowly, thoughtfully; not too 
much; do not drink carbonated beverages while eating; concentrate on your 
meal; common sense things.  Your appreciation for food will increase, as well 
as decreasing your hiccupping!