Thursday, March 10, 2011

Everybody yawns from unborn babies to the oldest great-grandparent. Animals do it, too. No one knows for sure why we yawn. Dr. Edward Hill explains more about yawning in todays 60 Second Housecall.

Dr. Hill:

Yawning involves opening the mouth involuntarily while taking a long, deep breath of air.

Yawning is a normal response to fatigue and drowsiness, but excessive yawning can be caused by a vasovagal reaction. This reaction is caused by the action of a nerve, called the vagus nerve, on the blood vessels. It may indicate a heart problem.

Medical science is not quite sure why we yawn. One theory is that a build-up of carbon monoxide or a low oxygen level in our blood triggers the yawning reflex.

Yawning is frequently associated with sleepiness, boredom or stretching. It is most common just after awakening or just before bedtime. It normally lasts about six seconds. Yawning can be observed as early as the eleventh week of life. Yawning can help expand the lungs and equalize the pressure in the middle ear.

To prevent excess yawning, get plenty of sleep at night and physical and mental stimulation during the day.

For North Mississippi Medical Center, Im Dr. Edward Hill.