II. Definitions
- Yawning
- Involuntary deep inspiration with the mouth open, typically stretched to maximal opening, followed by slow expiration
- Yawning, on average, lasts 5 seconds, and is often associated with drowsiness or boredom
- Often triggered when others yawn (or even reading or thinking about Yawning)
III. Physiology
- Yawning has a positive effect on arousal and Heart Rate, possibly from carotid body stimulation
- Yawning is often observed during times of low social interaction (e.g. lectures, studying, driving, watching television)
- Yawning may also provide another mechanism of Thermoregulation, providing cooling to counter Temperature increase
- Yawning clears eustachian tube pressure (similar to Valsalva Maneuver activity)
- Yawning is considered among empathy skills in humans (hence the triggered Yawning when others yawn)
IV. Causes: Excessive Yawning
- Opioid Withdrawal
- Multiple Sclerosis
- Epilepsy
- Migraine Headache
- Emotional Stress
- Anxiety
- Head Trauma
- Cerebrovascular Accident