Everyone yawns, yet the purpose of this body function is still somewhat of a mystery. People commonly yawn when they are tired or bored -- and when they see other people yawn. Excessive yawning, on the other hand, is not normal and can be a sign of a medical problem.
Yawning is an involuntary body process in which the mouth opens wide, and a deep breath is drawn, then exhaled. It's a common body function that humans share with most animals. Although the physiology and full purpose of yawning is still not clear, several theories exist, including research that yawning increases alertness and helps to cool the brain. Yawning is also linked to social communication, as the contagious aspect of yawning is a form of empathy -- and it's a nonverbal way to communicate boredom.
Excessive yawning may be related to drowsiness or sleep deprivation. This may simply be caused by a lack of sleep, or triggered by poor quality sleep -- from insomnia, sleep disturbance from shift work, or impaired sleep due to pain, illness or severe stress. Untreated sleep apnea, a disorder in which breathing repeatedly stops and starts during sleep, can also impair sleep quality. On the other hand, disorders that cause constant sleepiness, such as narcolepsy or hypersomnia, may also lead to an abundance of yawning.
Other Medical Causes
Excessive yawning may also be linked to a wide array of medical conditions, including multiple sclerosis, migraine headaches, schizophrenia, brain damage, heart disease, bleeding in or around the heart and epilepsy. The precise cause of the yawning, however, is not fully understood. One theory is that yawning -- and its brain-cooling effect -- is a corrective reflex in conditions associated with body heat regulation. Another potential reason for this symptom is a situation or underlying condition which triggers vasovagal syncope, which leads to a sudden drop in heart rate and blood pressure -- and symptoms such as yawning, dizziness, and fainting. Rarely, certain antidepressant medications, which work by increasing brain serotonin levels, are linked to excessive yawning.
Yawning is a normal body function, yet excessive yawning may signal a serious health problem. The best way to manage this symptom is to effectively treat the underlying condition. If the yawning is frequent and continuous, and not clearly linked to inadequate sleep, see your doctor as soon as possible. Rarely, excessive yawning is associated with a medical emergency, so if you also have symptoms such as fainting, dizziness, chest pain, shortness of breath or weakness, seek immediate medical attention.
Reviewed by Kay Peck, MPH RD
- International Journal of Applied and Basic Medical Research: Yawning and Its Physiological Significance
- Frontiers in Evolutionary Neuroscience: Changes in Physiology Before, During, and After Yawning
- Frontiers in Neuroscience: The Thermoregulatory Theory of Yawning: What We Know From Over 5 Years of Research
- Brain: Symptoms and Signs of Syncope: A Review of the Link Between Physiology and Clinical Clues