What Happens To Your Body When You Hold In A Yawn

There are many things we would rather not be caught doing in public — sneezing, passing gas, yawning ... the list goes on. Nobody wants to be seen mid-yawn while chatting with a close friend for fear of signaling to your pal that their story is essentially putting you to sleep. So what do you do? You try holding it in. But is holding in a yawn even physically possible, and are there any health hazards in doing so?

Many theories have been offered over the years as to why we yawn. For example, some studies have indicated that yawning may serve the purpose of keeping our brain temperature balanced (via Medical University of South Carolina). Additionally, research shows that yawning may serve as a means of stimulating focus and wakefulness through a release of hormones that make you more alert and boost the heart rate — so this may be why we yawn when we're either bored or tired. Experts at New Scientist reveal that animals, and even unborn babies, yawn as a natural function of the body. Interestingly, holding in this natural reaction can have both physical and social implications.

On a biological level, holding in a yawn interrupts the body's natural process of promoting blood flow to the brain, especially when the body is shifting between phases of the day that require differing amounts of physical activity and attention (via The Sleep Doctor). Therefore, by keeping the yawn in, you may be hindering your body's natural attempt at perking you up. In fact, a 2009 study in Inderscience Publishers found that analyzing yawns as part of an automobile's alarm system would prevent more roadside collisions by signaling to the driver that they may be getting tired — and that maybe it's time to pull over.

Additionally, yawning also plays a role in socialization. A study conducted by Baylor University discovered that yawning right after witnessing another person yawn is a sign of empathy and emotional connection. Study participants who did not yawn in response, on the other hand, were found to be more antisocial and have less empathetic character traits. Therefore, holding in a yawn may send an unintentional message to others of being a closed-off person.

Even so, despite your best efforts, if you still desire to hold back a yawn, you may find that you're out of luck. Much like when you're told that you can't do something and it makes you want to do it even more, the same holds true for yawns. According to TIME, research indicates that holding back a yawn only ups the body's desire to yawn even more — and unfortunately, our involuntary reflexes often win out.