What to Know About Yawning

Medically Reviewed by Dan Brennan, MD on June 15, 2021

You may not notice how often you yawn, or you may wonder why you can’t stop yawning. Yawning is a common reflex where you open your jaw wide, take in a deep breath, and then quickly exhale. Typically you’ll feel more relaxed right after you yawn. There’s not an exact reason why people yawn, but there are many theories.  

What Is Yawning?

Yawning has long been connected with feeling tired or bored. But, there are new studies that suggest this might not be true. Since there’s no known cause for yawning, these new studies offer theories for why you yawn. 

Newer studies suggest that yawning might do more than get oxygen to your brain. 

When you yawn, researchers think you may be communicating how you’re feeling: whether you’re tired, bored, or under mild stress. Some researchers think that yawning is an empathetic and social skill where we show that we connect with others. 

Reasons for Yawning

There's not any specific reason why you yawn. Regular yawning is a reflex in your body that just happens involuntarily, meaning that you do it without thinking about it. However, there are many things that researchers agree cause yawning. 

Change in elevation. If you’re in an airplane or driving in different elevations, you might yawn on purpose or as an automatic response from your body. This is your body equalizing the pressure in your ear. 

Empathy. Another cause of yawning is social empathy. If you see someone yawn or even read about yawning, you might have an urge to yawn. Psychologists say that you’re more likely to yawn when you see someone else do it if you’re more empathetic. The closer you are to someone, the more likely you’ll be to yawn if they do. 

Feeling bored or tired. Studies have shown that yawning isn’t a sign of being tired or feeling bored. Rather, it’s a reflex from your brain that makes you wake up or feel more alert. Yawning is your body’s way of trying to wake you up.

Cool your brain. Another unproven theory is that yawning is your body’s way of cooling your warm brain. The theory is that you will yawn more in situations where you’re overheated. Deep breaths and open mouths have been shown to cool the brain a little. However, there’s not enough evidence for this theory.  

Stretches your lungs and lung tissue. When you yawn, it’s sometimes followed by a larger stretch. By yawning, your body could be flexing your muscles and stretching your joints. You might also have an increased heart rate. By stretching your lungs and improving your heart, you’ll also feel more awake. 

Now that you know the possible reasons for yawning, you might pay more attention to when you yawn. Typically people don't notice their yawning unless it's happening more than usual. 

Is Excessive Yawning a Concern?

When you start to yawn a lot and you can't stop, you might begin to worry. Excessive yawning may be caused by an underlying condition. These conditions include: 

  • Sleep deprivation, or when you continually don't get enough sleep
  • Insomnia, a condition where you have trouble falling asleep or staying asleep
  • Sleep apnea, a condition that interrupts your breathing when you sleep
  • Narcolepsy, a condition that makes you excessively sleepy during the day

Excessive yawning may also be caused by taking medication that makes you very tired.

While excessive yawning may be a symptom of an underlying condition, sometimes it can be a symptom of a serious medical problem. These medical emergencies include: 

If you are doing something repetitive or not interesting to you, you might not be able to stop yawning. Tasks like watching television, listening to a lecture, studying, or driving can put you in a low-active state that makes you yawn more. 

Thermoregulatory disorders and intense headaches can also cause excessive yawning. Researchers believe this may be caused by a circulatory dysfunction. 

Not being able to stop yawning might be your body’s way of showing that your circulatory system isn’t working or that your body can’t regulate its body temperature. 

What to Do When You Can’t Stop Yawning

If you start yawning excessively and are not sure why, you should talk to your doctor. Excessive yawning might be caused by an underlying medical condition. It’s a good idea to ask your doctor what may be the cause. 

If you're worried that you can't stop yawning, you should see your doctor soon. You shouldn't ignore excessive yawning even though yawning is a common reflex. 

Show Sources


Interactive Journal of Medical Research: “Born to Yawn? Understanding Yawning as a Warning of the Rise in Cortisol Levels: Randomized Trial.”

International Journal of Applied & Basic Medical Research: “Yawning and its physiological significance.”

KidsHealth: "Why Do I Yawn"?

MUSC Health: “Yawning: Why & What Could It Mean?”

Neuroscience and Biobehavioral Reviews: “Why do we yawn?”

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