Possible medical causes of yawning include narcolepsy, sleep apnea and medications that treat anxiety or depression, according to Healthline. However, the more common causes are boredom and fatigue. Yawning may occur on its own or after seeing someone else yawn.
MRI scans can help doctors diagnose the underlying causes of frequent yawning, especially those related to the heart and brain. If medications are triggering excessive yawning, doctors may prescribe lower dosages, notes Healthline. Continuous positive airway pressure machines help patients yawning due to sleep apnea. Symptoms that may accompany frequent yawning include headache, abdominal cramping, balance problems and trouble with reading or writing, states Healthgrades.