Yawning can be caused by several factors besides sleepiness.
A classic symptom of fatigue, yawning can sometimes be a sign that your body is ready for sleep. It’s a common occurrence: Animals yawn, babies yawn, and adults yawn. But a yawn is not necessarily a sign that you are tired—check out these other potential causes.
1. Monkey See, Monkey Do.
The act of yawning is contagious. If you see someone yawn or read about yawning, you might do it yourself. This involuntary imitation may be related to the evolutionary history of yawning. A nonverbal cue that says it is time to relax, the trait may have been selected over time because it helps people coordinate their reactions to a changing environment with a larger group—changes like, say, darkness or the absence of a threat. So this is more of a social reason than a biological one.
2. You’re Compassionate.
People who have very empathetic personality traits and feel what others around them feel are more likely to mimic a yawn when they see other people yawning.
3. Your Brain is Hot.
Yawning may help regulate brain temperature. A warm brain might signal the body to yawn, which flexes walls of the sinus cavity and helps cool the important organ.
4. You’re Bored.
Without stimulation, people can start to feel sleepy. In other words, if you're staring at a wall, you're more likely to yawn than if you're watching a loud, bright music video on television.
5. You’re Preparing To Move.
Because it is linked to actions such as muscle stretching, joint movement, and an increased heart rate (think early morning waking), yawning may be part of the body’s way of gearing up for activity.
6. Your Body Wants You To Know Something Is Up.
It is not common, but in some cases, such as in people with epilepsy, yawning can signal an upcoming episode. In rare cases, excessive yawning may be a secondary symptom of a disease such as Parkinson’s or multiple sclerosis. However, underlying disease is not a common cause for this routine, normal response.