Have you ever find yourself sitting in a library when, all of a sudden, you start hiccuping loudly? This happened to a friend of mine the other day and I found myself thinking, why do we hiccup? What happens in our body when we do hiccup?

What is hiccuping and how does it work? 

Hiccuping results from uncontrollable spasms of the muscles that help us breathe. These muscles include our diaphragm (which is considered the major player of this response), the muscles between our ribs (intercostal muscles) and the muscles in our neck1. Our diaphragm sits under our lungs and above our stomach. Hiccuping forces us to inhale sharply and can also be referred to as singultus, which is a Latin term which is translated to mean ‘the act of catching one’s breath while sobbing’2.

The ‘hic’ sound that you hear when you hiccup is caused by diaphragm spasms. When your diaphragm contracts arbitrarily, it causes you to inhale; however, this inhalation is very short due to the rapid closing of a structure called the glottis3The glottis is the space between your vocal cords and it is its closing that causes the ‘hic’ sound.

Why do we hiccup?

It’s not really known exactly why we hiccup but here are some theories4:

  • Some scientists believe that we hiccup due to disruptions of the nervous system that leads to respiratory muscles (the muscles that help us breathe), which may be why some people hiccup when they’re upset, nervous, excited or exposed to different temperatures – this makes sense because we know the nervous system is directly related to all of these things!
  • For those everyday, arbitrary hiccups, it’s believed that overeating, drinking too much or eating/drinking too quickly are the causes. When you eat or drink too much, or too fast, your stomach expands to accommodate. Since your stomach sits below your diaphragm, its expansion will irritate the diaphragm, which will then contract and cause you to inhale.

Either way, your respiratory muscles are essentially acting out, causing you to rapidly inhale. The best way to stop hiccuping is likely to get in control of your breathing pattern, which is why holding your breath seems to work3!

1. Whitelaw, William A. 2007. What causes hiccups. ScientificAmerican.com. <http://www.scientificamerican.com/article.cfm?id=what-causes-hiccups&gt; January 30, 2013.

2. Wilkes, Garry. 2012. Hiccups. http://reference.medscape.com/ <http://emedicine.medscape.com/article/775746-overview&gt; January 30, 2013.

3. Murphy, Glenn. 2007. Why do we get hiccups and how do you stop them. http://www.sciencemuseum.org.uk/ <http://www.sciencemuseum.org.uk/onlinestuff/snot/why_do_we_get_hiccups_and_how_do_you_stop_them.aspx&gt; January 30, 2013.

4. n.p. 2004. Why do we hiccup. http://www.medicalnewstoday.com/ <http://www.medicalnewstoday.com/releases/7623.php&gt; January 30, 2013.