what causes excessive yawning and how to stop
Yawns can be caused by boredom. When watching an uninteresting performance, movie, or recital a person may have a bout of excessive yawning. To suppress the yawns, he can hold his mouth closed tightly and clench his jaws. When the yawn comes on he must keep the pressure in the rear of his jaws and swallow the yawn. Excessive yawning, caused by sleepiness, can be counteracted by drinking lots of water. Dehydration is a big cause of fatigue. When a person drinks a lot of water, the yawning will cease. Every time the urge to yawn is strong, drink a big gulp of water and the yawn will pass.