This points to one of the most important considerations in weighing the data: weighing it against the variable of whether the yawn is voluntary or involuntary. More research regarding voluntary yawns can help further develop these ideas on empathy and consciousness. Meanwhile further research on involuntary yawns could serve very useful for insight into schizophrenia and autism, as is suggested from the study performed at Duke.
#15. All the Good News We Have Discovered about Yawns Must Not Be Taken Too Far
While all these things about the positive health effects of yawns seem to be true, there is a limit. In the last section especially, where we just looked at the mental benefits, that are largely related to occasional voluntary yawns.
If you continuously yawn for a long period of time without any control over it, this is not a good thing. Of course, this can be a sign of being too tired. People who suffer from insomnia, sleep apnea, chronic fatigue syndrome, and other disorders related to unhealthy sleep cycles are likely to find themselves unable to control the large quantity of yawns that they produce and the extremely short amount of time between those many yawns.
However, just like yawns in general, excessive yawns are not necessarily related to tiredness. The action can be a symptom of heart disease, epilepsy, multiple sclerosis, and strokes. Excessive yawns can also be related to obesity. The rest of this section on health and yawns will deal with how yawns seem to relate –sometimes positively and sometimes negatively—to specific physical and mental disorder.