In the 4th century, Hippocrates first described yawning as a method of removing bad air, improving oxygen flow to the brain, and detecting early fever. Whilst this assertion dates back quite some time, it’s not entirely void of truth. Yawning is an involuntary deep breath, followed by a slow exhalation and the closing of the mouth. As many will know, yawning is often said to be contagious. You yawn when you see someone yawning, you see a picture of someone yawning, when you read about someone yawning, hear someone yawning, or even when you think about yawning.
Technically, yawning is a reflex in which air is deeply inhaled filling the lungs to capacity. The eardrum is stretched, and at the same time we hear a funny almost mechanical noise deep inside our head, followed by an inevitable full and long exhalation. There is a theory that yawning is a thermoregulating response by the body, i.e. yawning aids the cooling and temperature control of the brain, stopping our brains from overheating. Studies have been carried out to explore this theory, and the findings do show some support for it. In one study a cold stimulus to the forehead, such as a cooling pack, resulted in study participants yawning less. In fact yawning dropped by approximately 9% amongst this group.
Although not one of the primary signs or symptoms, yawning can be a response to and a sign of anxiety. Anxiety can change the body’s pattern of breathing and it can change the way the body receives its oxygen, causing changes in the amount of blood in your body. The yawn is the way the body reacts to a reduced intake of oxygen. Through yawning, the body absorbs an increased amount of air, similar to normal breathing, and helps the person to feel energetic and awake. As an anxious person begins to feel increasingly anxious, they may very well find themselves yawning more and more.
Not only is yawning associated with anxiety, it is also associated with other bodily states such as stress, boredom and even hunger. Yawning is also very commonly associated with sleep, it is associated with the period both before and after sleep. It occurs when the body is under high stress, such as high blood pressure or high cholesterol. This can be during the first minutes of sleep, often before, during or just after sleep.
People yawn for the first time in the womb, taking both their first breath and their first yawn in the womb and from that point forward they will yawn (and obviously also breathe) their whole lives. Although yawning is contagious that’s not to say you can’t yawn when you’re alone. You can of course yawn without it being prompted directly by someone else.
Whilst some people find yawning contagious, approximately two thirds of people, not all people do. Yawning is also thought to be a sign of empathy. One study uncovered that contagious yawning does not happen in people until about the age of 4, around the same age empathy and other such emotions start to develop in children. A further study discovered that the closer you are to someone who yawns the more you too will yawn, and that yawns are most contagious amongst family members.
Whilst yawning is very common and nothing remarkable. Not all yawing is good news though, excessive or very frequent yawning can indicate or accompany a number of serious health problems, such as high blood pressure, heart disease, diabetes, epilepsy, multiple sclerosis and liver failure. Excessive yawning can also be common amongst people who’ve had a stroke. Depending on the cause, excessive yawning can occur if you feel very tired, have difficulty concentrating and / or have difficulty breathing. When people have difficulty getting enough sleep, they may also find that they yawn a lot more than usual. Excessive yawning can therefore go hand in hand with many common sleep disorders.
Even if you manage to get a good 8 hours of sleep, you can yawn first thing the next morning. That first yawn of the day is usually the first time in the day we stretch out the intercostal muscles surrounding the lungs to absorb more oxygen, setting us up for the long day ahead. Yawning is a very normal phenomenon and for the vast majority, it signals nothing more sinister than tiredness or perhaps mild anxiety. But anyone who may be worried about excessive yawning should probably consult a medical professional if just to put their mind at ease.