Yawning is a normal response to fatigue and drowsiness , but excessive yawning can be caused by a vasovagal reaction and may indicate a heart problem.
Most insomniacs are too anxious to be sleepy in spite of their short nightly sleep time.
There may be other causes of excessive yawning. This list is not all inclusive, and the causes are not presented in order of likelihood. The causes of this symptom can include unlikely diseases and medications. Furthermore, the causes may vary based on age and gender of the affected person, as well as on the specific characteristics of the symptom such as time course, aggravating factors, relieving factors, and associated complaints. Use the Symptom Analysis option to explore the possible explanations for excessive yawning, occurring alone or in combination with other problems.