Yawning is a natural response to feeling tired or bored, and it is usually triggered by sleepiness or fatigue. However, excessive yawning may be a symptom of an underlying medical condition. Some of the most common medical problems associated with excessive yawning are sleep deprivation, insomnia, sleep apnea, and depression. Other possible causes of excessive yawning include:

• Sleep disorders: such as narcolepsy and sleep apnea.
• Medications: some medications, such as selective serotonin reuptake inhibitors (SSRIs) used to treat depression and anxiety disorders, can cause excessive yawning.
• Neurological disorders: many neurological disorders can cause excessive yawning, such as epilepsy, multiple sclerosis, and strokes.
• Vasovagal reaction: a stimulation of the vagus nerve caused by heart attack or aortic dissection.
• Thermoregulatory disorders and intense headaches: these can also cause excessive yawning.

If you find yourself yawning excessively, it may be best to schedule an appointment with a doctor to determine the underlying cause.